How do you call a function in a redirect field?

Question

I think it would be better to show you the code first before I explain:

$(function() {
    var IMP=window.IMP;
    IMP.init('11111111');
    $('.order-form').on('submit', function(e) {
        var amount = parseFloat($('.order-form input[name="amount"]').val().replace(',',''));
        var type=$('.order-form input[name="type"]:checked').val();
        var order_id = AjaxCreateOrder(e);
        if(order_id==false) {
            alert('주문 생성 실패\n다시 시도해주세요.');
            return false;
        }

        var merchant_id = AjaxStoreTransaction(e, order_id, amount, type);

        if(merchant_id!=='') {
            IMP.request_pay({
                merchant_uid:merchant_id,
                name:'Product',
                buyer_name:$('input[name="first_name"]').val()+" "+$('input[name="last_name"]').val(),
                buyer_email:$('input[name="email"]').val(),
                amount:amount,
                m_redirect_url: 'mywebsite/payments/complete',
            }, function(rsp) {
                if(rsp.success) {
                    var msg = '결제가 완료되었습니다.';
                    msg += '고유 ID : '+rsp.imp_uid;
                    // 결제 완료후 보여줄 메시지
                    ImpTransaction(e, order_id, rsp.merchant_uid, rsp.imp_uid, rsp.paid_amount);
                } else {
                    var msg = '결제에 실패하였습니다.';
                    msg += '에러내용 : '+ rsp.error_msg;
                    console.log(msg);
                }
            });
        }
        return false;
    });
});


function ImpTransaction(e, order_id, merchant_id, imp_id, amount) {
    e.preventDefault();
    var request = $.ajax({
        method:"POST",
        url:order_validation_url,
        async:false,
        data:{
            order_id:order_id,
            merchant_id:merchant_id,
            imp_id:imp_id,
            amount:amount,
            csrfmiddlewaretoken:csrf_token
        }
    });
    request.done(function(data) {
        if(data.works) {
            $(location).attr('href',location.origin+order_complete_url+'?order_id='+order_id)
        }
    });
    request.fail(function(jqXHR, textStatus) {
        if(jqXHR.status == 404) {
            alert("페이지가 존재하지 않습니다.");
        } else if(jqXHR.status==403) {
            alert("로그인 해주세요.");
        } else {
            alert("문제가 발생했습니다.\n다시 시도해주세요.");
        }
    });
}

As you can see, I am using an Iamport(IMP) API, but that is not really important. What I want is when I run the m_redirect_url: 'mywebsite/payments/complete', I want to be able to run the ImpTransaction() simultaneously before reirecting to the url mywebsite/payments/complete. This is because the callback function function(rsp) does not work when I am using my django website on mobile. m_redirect_url is the url I redirect the user to once the transaction is complete in mobile.

Thank you, and please leave any comments or questions you have below.