Ajax with Promise, i dont know why...

//Frontend Part
function getNextDse(node, rs, rj) {
    let string_json = JSON.stringify(assocnodes);
    $.ajax({
        type: "POST",
        url: "magic.php",
        data: {
            'nodes': string_json,
            'action': 'GetEquipmentCodeAndTitleByProductCode'
        },
        dataType: "json",
        success: function(data) {
            let searchnode;
            $(data).each(function(index, element) {
                debugger;
                if (element.dse !== "") {
                    searchnode = $(document).find("[id='dse_" + element.node_id + "']");
                    searchnode.data("sql", JSON.stringify(element.dse));
                    searchnode.show();
                }
            });
            rs();
        },
        error: function(XMLHttpRequest, textStatus, errorThrown) {
            console.log(textStatus);
            debugger;
            rj();
        }
    });
}

$(document).ready(function() {
    let assocnodes = [];

    $('.dse_equipment').each(function(index, element) {
        $(element).attr('id', 'dse_' + index);
        assocnodes.push({
            node_id: index,
            data: element.dataset.dse
        });
    });

    $('.equipment_show').on('click', function(e) {
        $('.spinner').fadeIn();
        let awaits = new Promise(function(rs, rj) {
            getNextDse(assocnodes, rs, rj)
        });
        awaits.then(results => {
            $(".spinner").fadeOut();
        });
    });
});



//Backend part
<?php
define("_INC", 1);
require_once ("./cmsconf.php");
sql_connect2();
if($_POST['action'] === 'GetEquipmentCodeAndTitleByProductCode'){
  $RetArr = [];
  $i = 0;
  foreach (json_decode($_POST['nodes']) as $value){
    $RetArr[$i] = [];
    $RetArr[$i]['node_id'] = $value->node_id;
    $RetArr[$i]['dse'] = sqltab_i('
                        SELECT
                        equipment.id,
                        equipment.code,
                        equipment.title
                        FROM `equipment_products`
                        LEFT JOIN products ON products.id = product_id
                        LEFT JOIN equipment ON equipment.id = equipment_id
                        WHERE products.code = "'.$value->data .'" GROUP BY equipment.id;');
    $i++;
  }
  echo json_encode($RetArr);
}
?>