I’m trying to add a simple line in a div, but append doesn’t work, alert and set values dont work

                    <script>
                        $('#salvaprod').on('click', function() {
                            $.ajax({
                              type: 'post',
                              url: 'lcompras_add_sql.php',
                              datatype: 'html',
                                data: {
                                   qtdp: $('#qtdp').val(),
                                   produtop: $('#produtop').val(),
                                }
                            }).done(function(data) {
                                requisitarPagina('') //it insert on database
                            })
                        })
                        function requisitarPagina(url) {
                            let ajax = new XMLHttpRequest();
                            ajax.open('POST', url)

                            parent.jQuery.fancybox.close();
                            ajax.onreadystatechange = () => {

                              if(ajax.readyState == 4 && ajax.status == 200) {
                                // add no extrato
                                alert("ttt"); //Alert doesnt work
                                html='<div class="cx_item"><i class="fa-regular fa-circle-right"></i> '+$('#qtdp').val()+'x '+$('#produtop').val()+'</div>';
                                $("#listac").append(html);//append doesnt work
                                document.getElementById('qtdp').value = '1'; //Values not reseted
                                document.getElementById('produtop').value = '';//Values not reseted
                                $.wnoty({
                                  // 'success', 'info', 'error', 'warning'
                                  type:'success',
                                  message:'Produto adicionado com sucesso',
                                  autohideDelay: 5000,// 5 seconds
                                  // "top-left", "bottom-left", "top-right", "bottom-right"
                                  position:'top-right',
                                });//wnoty works fine
                                console.log(html) //does not log
                              }
                              if(ajax.readyState == 4 && ajax.status == 404) {
                                //document.getElementById('resultado').innerHTML = '.. tente novamente mais tarde :s ..'
//                                        document.getElementById('modal').style.visibility = 'hidden'
                                $.wnoty({
                                  // 'success', 'info', 'error', 'warning'
                                  type:'error',
                                  message:'Produto não incluido, tente novamente',
                                  autohideDelay: 7000,// 5 seconds
                                  // "top-left", "bottom-left", "top-right", "bottom-right"
                                  position:'top-right',
                                });
                              }
                            }
                            ajax.send()
                            console.log(ajax)
                          }
                    </script>

The data is inserted on DB, I get wnoty notification but html doesn’t append to listac div.

Tried lots of different syntaxes, tried even alert, just before append, but that didn’t work either.

tried change sintaxes, tried just a simple alert, not working…