When jquery defer, the menu js file gives an error and the menu does not work

Question

Source of JS File: https://kargotakip.co/kargom-nerede/themes/trackco/js/customscript.js

Desktop and mobile menu not working. Click for picture

This js file is controlling the dropdown in my theme. Unfortunately, when I defer the jquery library, it gives this error. But if jquery doesn't defer, if the script loads normally, it works fine.

jQuery.fn.exists = function(callback) {
    var args = [].slice.call(arguments, 1);
    if (this.length) {
        callback.call(this, args);
    }
    return this;
};


/*----------------------------------------------------
/* Make all anchor links smooth scrolling
/*--------------------------------------------------*/
jQuery(document).ready(function($) {
 // scroll handler
    var scrollToAnchor = function( id, event ) {
        // grab the element to scroll to based on the name
        var elem = $("a[name='"+ id +"']");
        // if that didn't work, look for an element with our ID
        if ( typeof( elem.offset() ) === "undefined" ) {
            elem = $("#"+id);
        }
        // if the destination element exists
        if ( typeof( elem.offset() ) !== "undefined" ) {
            // cancel default event propagation
            event.preventDefault();

            // do the scroll
            // also hide mobile menu
            var headerHeight = $("#header.sticky-navigation").height() + 15; // Get fixed header height
            if( headerHeight > 0 ){
                var scroll_to = elem.offset().top-headerHeight;
            } else {
                var scroll_to = elem.offset().top;
            }
            $('html, body').removeClass('mobile-menu-active').animate({
                            scrollTop: scroll_to
            }, 600, 'swing', function() { if (scroll_to > 46) window.location.hash = id; } );
        }
    };
    // bind to click event
    $("a").click(function( event ) {
        // only do this if it's an anchor link
        var href = $(this).attr("href");
        var exclude = ['#tab-description', '#tab-additional_information', '#tab-reviews'];
        if (exclude.includes(href)) {
            return;
        }
        if ( href && href.match("#") && href !== '#' ) {
            // scroll to the location
            var parts = href.split('#'),
                url = parts[0],
                target = parts[1];
            if ((!url || url == window.location.href.split('#')[0]) && target)
                scrollToAnchor( target, event );
        }
    });
});


/*----------------------------------------------------
/* Responsive Navigation
/*--------------------------------------------------*/
if (mts_customscript.responsive && mts_customscript.nav_menu != 'none') {
        jQuery(document).ready(function($){
                $('#secondary-navigation').append('<div id="mobile-menu-overlay" />');
                // merge if two menus exist
                if (mts_customscript.nav_menu == 'both' && !$('.navigation.mobile-only').length) {
                        $('.navigation').not('.mobile-menu-wrapper').find('.menu').clone().appendTo('.mobile-menu-wrapper').hide();
                }
                $('nav').find('.header-social-icons').clone().appendTo('.mobile-menu-wrapper').hide();
                $('nav').find('.mts-cart').clone().appendTo('.mobile-menu-wrapper').hide();

                $('.toggle-mobile-menu').click(function(e) {
                        e.preventDefault();
                        e.stopPropagation();
                        $('body').toggleClass('mobile-menu-active');

                        if ( $('body').hasClass('mobile-menu-active') ) {
                                if ( $(document).height() > $(window).height() ) {
                                        var scrollTop = ( $('html').scrollTop() ) ? $('html').scrollTop() : $('body').scrollTop();
                                        $('html').addClass('noscroll').css( 'top', -scrollTop );
                                }
                                $('#mobile-menu-overlay').fadeIn();
                        } else {
                                var scrollTop = parseInt( $('html').css('top') );
                                $('html').removeClass('noscroll');
                                $('html,body').scrollTop( -scrollTop );
                                $('#mobile-menu-overlay').fadeOut();
                        }
                });
    **}).on('click', function(event) {
        var $target = jQuery(event.target);
        if ( ( $target.hasClass("fa") && $target.parent().hasClass("toggle-caret") ) ||  $target.hasClass("toggle-caret") ) {// allow clicking on menu toggles
            return;
        }
        jQuery('body').removeClass('mobile-menu-active');
        jQuery('html').removeClass('noscroll');
        jQuery('#mobile-menu-overlay').fadeOut();
    });**

}

/*----------------------------------------------------
/*  Dropdown menu
/* ------------------------------------------------- */
jQuery(document).ready(function($) {
        let $pullToggle = $('#pull');
        function mtsDropdownMenu() {
                if(!$pullToggle.is(':visible')) {
                        let timer;
                        let delay = 100;
                        $('.navigation li').hover(function (e) {
                            if (e.type === 'mouseenter') {
                                e.preventDefault();
                                let $this = $(this);
                                timer = setTimeout(function () {
                                    $this.children('ul.sub-menu, ul.children').slideDown('fast');
                                }, delay);
                            }
                            else if (e.type === 'mouseleave') {
                                e.preventDefault();
                                $(this).children('ul.sub-menu, ul.children').hide(1);
                                clearTimeout(timer);
                            }
                        });
                        
                        } else {
                            $('.navigation li').unbind('mouseenter mouseleave');
                            //$('.navigation li.active > ul.sub-menu, .navigation li.active > ul.children').show();
                        }
        }

        mtsDropdownMenu();

        $(window).resize(function() {
                mtsDropdownMenu();
        });
});

/*---------------------------------------------------
/*  Vertical menus toggles
/* -------------------------------------------------*/
jQuery(document).ready(function($) {

        $('.widget_nav_menu, .navigation .menu').addClass('toggle-menu');
        $('.toggle-menu ul.sub-menu, .toggle-menu ul.children').addClass('toggle-submenu');
        $('.toggle-menu ul.sub-menu').parent().addClass('toggle-menu-item-parent');

        $('.toggle-menu .toggle-menu-item-parent').append('<span class="toggle-caret"><i class="fa fa-plus"></i></span>');

        $('.toggle-caret').click(function(e) {
                e.preventDefault();
                $(this).parent().toggleClass('active').children('.toggle-submenu').slideToggle('fast');
        });
});

/*----------------------------------------------------
/* Social button scripts
/*---------------------------------------------------*/
jQuery(document).ready(function($){
    (function(d, s) {
        var js, fjs = d.getElementsByTagName(s)[0], load = function(url, id) {
        if (d.getElementById(id)) {return;}
        js = d.createElement(s); js.src = url; js.id = id;
        fjs.parentNode.insertBefore(js, fjs);
        };
    jQuery('span.facebookbtn, span.facebooksharebtn, .facebook_like').exists(function() {
        load('//connect.facebook.net/en_US/all.js#xfbml=1&version=v2.8', 'fbjssdk');
    });
    jQuery('span.twitterbtn').exists(function() {
        load('//platform.twitter.com/widgets.js', 'tweetjs');
    });
    jQuery('span.linkedinbtn').exists(function() {
        load('//platform.linkedin.com/in.js', 'linkedinjs');
    });
    jQuery('span.pinbtn').exists(function() {
        load('//assets.pinterest.com/js/pinit.js', 'pinterestjs');
    });
    jQuery('span.stumblebtn').exists(function() {
        load('//platform.stumbleupon.com/1/widgets.js', 'stumbleuponjs');
    });
    }(document, 'script'));
});

/*----------------------------------------------------
/* Lazy load avatars
/*---------------------------------------------------*/
if ( mts_customscript['lazy_load_comments'] ) {
        jQuery(document).ready(function($){
                var lazyloadAvatar = function(){
                        $('.comment-author .avatar').each(function(){
                                var distanceToTop = $(this).offset().top;
                                var scroll = $(window).scrollTop();
                                var windowHeight = $(window).height();
                                var isVisible = distanceToTop - scroll < windowHeight;
                                if( isVisible ){
                                        var hashedUrl = $(this).attr('data-src');
                                        if ( hashedUrl ) {
                                                $(this).attr('src',hashedUrl).removeClass('loading');
                                        }
                                }
                        });
                };
                if ($('.comment-author .avatar').length > 0) {
                    $('.comment-author .avatar').each(function (i, el) {
                        $(el).attr('data-src', el.src).removeAttr('src').addClass('loading');
                    });
                    $(function () {
                        $(window).scroll(function () {
                            lazyloadAvatar();
                        });
                    });
                    //lazyloadAvatar();
                }
        });
}

/*
* Detect browser width for sticky navigation
*/
jQuery(document).ready(function ($) {
    // check mobile width
    function checkmobilesize() {
        var wi = $(window).width();
        if (wi <= 865) {
            $header = $('#header');
            if ($header.hasClass('sticky-navigation')) {
                $header.removeClass('sticky-navigation');
            }
            if ($header.hasClass('sticky-navigation-active')) {
                $header.removeClass('sticky-navigation-active');
            }
            $('#catcher').remove();
        }
    }
    // check desktop width
    function checkdesktopsize() {
        var wi = $(window).width();
        if (wi > 865) {
            $header = $('#header');
            if (!$header.hasClass('sticky-navigation')) {
                $header.addClass('sticky-navigation');
            }
        }
    }
    if ('0' == mts_customscript.mobile_sticky) {
        checkmobilesize();
    }
    $(window).resize(function ($) {
        if ('0' == mts_customscript.mobile_sticky) {
            checkmobilesize();
            if ('1' == mts_customscript.desktop_sticky) {
                checkdesktopsize();
            }
        }
    });
});

I tried to load the jquery.min.js file with async but still no result. In Lighthouse, jquery.min.js wastes a lot of time and lowers my pagespeed score. For this reason, I want to install jquery.min.js as a defer, but the menu does not work.