Add a button to Select2 Dropdown list

I am using the lastest version of Select2. Want to add an Insert New button at the end of the dropdown list. I tried these two solutions I found online

Solution 1:

$(".select2-drop").append('<table width="100%"><tr><td class="row"><button class="btn btn-block btn-default btn-xs" onClick="modal()">Add new Item</button></div></td></tr></table>');

Solution 2

$("#itemId0").select2("container").find("div.select2-drop").append('<table width="100%"><tr><td class="row"><button class="btn btn-block btn-default btn-xs" onClick="modal()">Add new Item</button></div></td></tr></table>');

With Solution 1 nothing happens. With solution 2 I get the error message in the select 2 js file

0x800a138f - JavaScript runtime error: Unable to get property 'apply' of undefined or null reference

Can anyone please help?

Here is my HTML

  <select id='itemId0' name='product[0][name]' class='form-control col-lg-5 itemSearch' >
                                <option></option>
                            </select>

AND the full select2 javascritp

           function productFormatResult(product) {
            if (product.loading) product.text;
            var html = "<table><tr>";
            html += "<td>";
            html += product.text;
            html += "</td></tr></table>";

            return html;
        }
        //  alert(html);
        function productFormatSelection(product) {
            var selected = "<input type='hidden' name='itemId' value='" + product.id + "'/>";
            return selected + product.text;
        }

        //$("#itemId0").select2();
        $("#itemId0").select2({

            ajax: {
                url: "@Url.Action("GetProducts", "Inventories")",
                dataType: 'json',
                data: function (params) {
                    return {
                        q: params.term
                    };
                },
                processResults: function (data, params) {
                    return { results: data };
                },
                cache: true
            },
            escapeMarkup: function (markup) { return markup; },
            minimumInputLength: 1,
            templateResult: productFormatResult,
            templateSelection: productFormatSelection,
            dropdownClass: 'bigdrop'
        });
       // $(".select2-drop").append('<table width="100%"><tr><td class="row"><button class="btn btn-block btn-default btn-xs" onClick="modal()">Add new Item</button></div></td></tr></table>');
        $("#itemId0").select2("container").find("div.select2-drop").append('<table width="100%"><tr><td class="row"><button class="btn btn-block btn-default btn-xs" onClick="modal()">Add new Item</button></div></td></tr></table>');

check it

$('#select2').select2({
       placeholder: 'This is my placeholder',    
         language: {
             noResults: function() {
            return `<button style="width: 100%" type="button"
            class="btn btn-primary" 
            onClick='task()'>+ Add New Item</button>
            </li>`;
            }
         },
       
        escapeMarkup: function (markup) {
            return markup;
        }
    });
    

Update: (Explanation)

If you need to add button in select2 if no result found you just need to returnHTML Button code from noResults function and Add escapeMarkup function to render custom templates.

language: {
         noResults: function() {
        return `<button style="width: 100%" type="button"
        class="btn btn-primary" 
        onClick='task()'>+ Add New Item</button>
        </li>`;
        }
     },

    escapeMarkup: function (markup) {
        return markup;
    }

Try below example to see how it looks.

https://jsfiddle.net/Hamza_T/yshjqw85/32/