JQuery wait for createElement (image) - http/2 error

Question

I switched to HTTP/2 and now I sometimes get errors when appending new images.

Currently using JQuery.

var logoCarousel = {
    initCarousel: function () {
        ...
        var rows = $('.section.section--logos .content .logo__row');
        var row1 = $(rows[0]);

        // LOOP ELEMENTS
        $.each(initUsedElements, function () {
            self.appendElement(this, row1, 1);
            // self.appendElement(this, row2, 2);
        });
    },
    appendElement: function (elementsInput, row, rowNum) {
        if (row.attr("data-actual-count") != row.attr("data-max-count") && elementsInput.flag == false) {
            let img = document.createElement("img");
            img.setAttribute('src', elementsInput.url);
            img.setAttribute('alt', '');
            img.setAttribute('data-actual-id', elementsInput.id);
            img.setAttribute('class', 'client__logo');

            row.prepend(img);

            row.attr("data-actual-count", parseInt(row.attr("data-actual-count")) + 1);
            elementsInput.flag = true;
            elementsInput.lastRow = rowNum;

            return elementsInput;
        }
    },
};

I am getting net::ERR_HTTP2_PROTOCOL_ERROR.

If I understand correctly my problem is I do not wait in the $.each-loop until the image is loaded.

How can I do this?