I get no errors, just an empty table that says: No matching records found

Working response from adapted "ssp.class.php" script provided in the web:

{"draw":0,"recordsTotal":7,"recordsFiltered":7,"data":[{"id_cliente":"row_2","nombre":"jose","apellido":null,"domicilio":null,"localidad":"bs as","alta_fecha":null,"telefono":"1157446780","documento":null},... some other responses, }]}

Response from API rest (added some counts operations to match the SSP example:

{"draw":0,"recordsTotal":7,"recordsFiltered":7,"data":[{"id_cliente":"row_9","nombre":"JOSE","apellido":"ENRIQUE","domicilio":"LIBERTADOR
4000","localidad":"gonzalez catan","alta_fecha":"2020-11-13
10:29:11","telefono":"1157446780","documento":"180180"},... some other responses, }]}

JS for loading the table

$(document).ready(function() {
    var table = $('#tablaClientes').DataTable( {
        "language": {
              "url":"assets/dist/json/Spanish.json"
            },
        "serverSide": true,
        ajax: {
        url: 'http://localhost/codoacodo_php/api/clientes/read.php'  //<Not working, tried also   api/clientes/read.php
    },
//        "ajax": "data/getClientes.php", <<Working fine, this is the SSP::complex test. Made with the test script in the page
         "columns": [
            {
                "className":      'details-control',
                "orderable":      false,
                "data":           null,
                "defaultContent": '',
                "render": function () {
                 return '<i class="fa fa-plus-square" aria-hidden="true"></i>';   
                }                         
            },
            { "data": "id_cliente" },
            { "data": "nombre" },
            { "data": "apellido" },
            { "data": "documento" }
        ],
        "order": [[1, 'asc']]
    } );

ANY suggestion is greatly appreciated. Cheers!