How to load data from OAuth and process in dataTable?

Question

JavaScript

The task is to get data from forms (forms on gravity forms, wordpress, work with them via API), there is a consumer key and a secret key. When using a normal Ajax request, the data arrives, but it is not possible to make friends with dataTables.

Authorization source code:

const oauth = OAuth({
      consumer: {
        key: '[ck_...]',
        secret: '[cs_...]'
      },
      signature_method: 'HMAC-SHA1',
      hash_function(base_string, key) {
        return CryptoJS.HmacSHA1(base_string, key).toString(CryptoJS.enc.Base64);
      }
    });

    const request_data = {
      url: 'https://...path...',
      method: 'GET'
    };

    const token = {
      key: '[key]',
      secret: '[secret]'
    };

Ordinary ajax receiving that works:

$.ajax({
      url: request_data.url,
      type: request_data.method,
      data: oauth.authorize(request_data)
    }).done(function(data) {
      console.log(data);
    });

As part of dataTable initialization (doesn't work):

function getEndpoint() {
      
      $.ajax({
        url: request_data.url,
        type: request_data.method,
        data: oauth.authorize(request_data),
        dataSrc: function(data) { 
         console.log('Test'); // На этом уровне = уже ничего не выводится в консоль
          let entries = data.entries; 
          let modified = [];
          for (var i = 0; i < entries.length; i++) { 
            modified.push({
              'checkbox-cell': '<label class="b-checkbox checkbox"><input type="checkbox" true-value="true" value="false"> <span class="check"></span> <span class="control-label"></span></label>',
              'id_tag': `<a href="javascript:void(0);" class="tablerow_ID" data-id="${entries[key].id}">${entries[key].id}</a>`,
              'created_at_display': `<span class="tablerow_date">${new Intl.DateTimeFormat().format(new Date(entries[key].date_created))}</span>`,
              'created_at_system': entries[key].date_created,
              'name': `<span class="tablerow_name">${entries[key][21.3]} ${entries[key][21.6]}</span>`,
              'address': entries[key][2],
              'city': entries[key][1],
              'status': '<span data-dest="status" class="tag is-light">' + getStatus(entries[key].status) + '</span>',
              'owner': '<span data-dest="handler" class="tag is-custom">' + getHandler(entries[key].handler) + '</span>'
            });
          }
          return modified;
        }
      });
    }

$('#applications').DataTable({
      ajax: getEndpoint(),
      columns: [
        {data: 'checkbox-cell'},
        {data: 'id_tag'},
        {data: {
          _: 'created_at_display',
          sort: 'created_at_system',
        }},
        {data: 'name'},
        {data: 'address'},
        {data: 'city'},
        {data: 'status'},
        {data: 'owner'},
      ],
...
});

What's wrong?