<?php

$sql = "
    SELECT url_payment_gateway, apikey_payment_gateway, tokenkey_payment_gateway
    FROM data_server
    WHERE id = :id
";

$stmt = $this->pdo->prepare($sql);
$stmt->execute(['id' => $_SESSION['server_id']]);

$result = $stmt->fetch();

return [
    'url_endpoint'  => $result ['url_payment_gateway'],
    'client_id'     => $result ['apikey_payment_gateway'],
    'secret_key'    => $result ['tokenkey_payment_gateway']
];