Getting a 500 Internal Server Error Jquery

While everything is running in the software, I get this error when I make a selection from the dropdown list in only one part. Where am I making a mistake? or is it a server error? I have not received this error in any Laravel before. When trying to get something from a dropdown list, this error comes to the console and there is no reaction on the site.

https://prnt.sc/vaujzf

<script type="text/javascript">
    $("ul#product").siblings('a').attr('aria-expanded','true');
    $("ul#product").addClass("show");
    $("ul#product #adjustment-create-menu").addClass("active");
var lims_product_array = [];
var product_code = [];
var product_name = [];
var product_qty = [];

    $('.selectpicker').selectpicker({
        style: 'btn-link',
    });

    $('#lims_productcodeSearch').on('input', function(){
        var warehouse_id = $('#warehouse_id').val();
        temp_data = $('#lims_productcodeSearch').val();
        if(!warehouse_id){
            $('#lims_productcodeSearch').val(temp_data.substring(0, temp_data.length - 1));
            alert('Please select Warehouse!');
        }
    });

    $('select[name="warehouse_id"]').on('change', function() {
        var id = $(this).val();
        $.get('getproduct/' + id, function(data) {
            lims_product_array = [];
            product_code = data[0];
            product_name = data[1];
            product_qty = data[2];
            $.each(product_code, function(index) {
                lims_product_array.push(product_code[index] + ' (' + product_name[index] + ')');
            });
        });
    });

    var lims_productcodeSearch = $('#lims_productcodeSearch');

    lims_productcodeSearch.autocomplete({
        source: function(request, response) {
            var matcher = new RegExp(".?" + $.ui.autocomplete.escapeRegex(request.term), "i");
            response($.grep(lims_product_array, function(item) {
                return matcher.test(item);
            }));
        },
        response: function(event, ui) {
            if (ui.content.length == 1) {
                var data = ui.content[0].value;
                $(this).autocomplete( "close" );
                productSearch(data);
            };
        },
        select: function(event, ui) {
            var data = ui.item.value;
            productSearch(data);
        }
    });

    $("#myTable").on('input', '.qty', function() {
        rowindex = $(this).closest('tr').index();
        checkQuantity($(this).val(), true);
    });

    $("table.order-list tbody").on("click", ".ibtnDel", function(event) {
        rowindex = $(this).closest('tr').index();
        $(this).closest("tr").remove();
        calculateTotal();
    });

    $(window).keydown(function(e){
        if (e.which == 13) {
            var $targ = $(e.target);
            if (!$targ.is("textarea") && !$targ.is(":button,:submit")) {
                var focusNext = false;
                $(this).find(":input:visible:not([disabled],[readonly]), a").each(function(){
                    if (this === e.target) {
                        focusNext = true;
                    }
                    else if (focusNext){
                        $(this).focus();
                        return false;
                    }
                });
                return false;
            }
        }
    });

    $('#adjustment-form').on('submit',function(e){
        var rownumber = $('table.order-list tbody tr:last').index();
        if (rownumber < 0) {
            alert("Please insert product to order table!")
            e.preventDefault();
        }
    });

    function productSearch(data){
        $.ajax({
            type: 'GET',
            url: 'lims_product_search',
            data: {
                data: data
            },
            success: function(data) {
                var flag = 1;
                $(".product-code").each(function(i) {
                    if ($(this).val() == data[1]) {
                        rowindex = i;
                        var qty = parseFloat($('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ') .qty').val()) + 1;
                        $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ') .qty').val(qty);
                        checkQuantity(qty);
                        flag = 0;
                    }
                });
                $("input[name='product_code_name']").val('');
                if(flag){
                    var newRow = $("<tr>");
                    var cols = '';
                    cols += '<td>' + data[0] + '</td>';
                    cols += '<td>' + data[1] + '</td>';
                    cols += '<td><input type="number" class="form-control qty" name="qty[]" value="1" required step="any" /></td>';
                    cols += '<td class="action"><select name="action[]" class="form-control act-val"><option value="-"></option><option value="+"></option></select></td>';
                    cols += '<td><button type="button" class="ibtnDel btn btn-md btn-danger"></button></td>';
                    cols += '<input type="hidden" class="product-code" name="product_code[]" value="' + data[1] + '"/>';
                    cols += '<input type="hidden" class="product-id" name="product_id[]" value="' + data[2] + '"/>';

                    newRow.append(cols);
                    $("table.order-list tbody").append(newRow);
                    rowindex = newRow.index();
                    calculateTotal();
                }  
            }
        });
    }

    function checkQuantity(qty) {
        var row_product_code = $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ')').find('td:nth-child(2)').text();
        var action = $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ')').find('.act-val').val();
        var pos = product_code.indexOf(row_product_code);

        if ( (qty > parseFloat(product_qty[pos])) && (action == '-') ) {
            alert('Quantity exceeds stock quantity!');
            var row_qty = $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ')').find('.qty').val();
            row_qty = row_qty.substring(0, row_qty.length - 1);
            $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ')').find('.qty').val(row_qty);
        }
        else {
            $('table.order-list tbody tr:nth-child(' + (rowindex + 1) + ')').find('.qty').val(qty);
        }
        calculateTotal();
    }

    function calculateTotal() {
        var total_qty = 0;
        $(".qty").each(function() {

            if ($(this).val() == '') {
                total_qty += 0;
            } else {
                total_qty += parseFloat($(this).val());
            }
        });
        $("#total-qty").text(total_qty);
        $('input[name="total_qty"]').val(total_qty);
        $('input[name="item"]').val($('table.order-list tbody tr:last').index() + 1);
    }
</script>

via Chebli Mohamed