auth-proxy.php

<?php

header('Content-Type: application/json');
header("Access-Control-Allow-Origin: *"); 

$username = 'TU_USERNAME';
$password = 'TU_PASSWORD';

$api_url = "https://el-api-de-pepe-donis.com/auth";

$ch = curl_init($api_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");

$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

http_response_code($http_code);

echo $response;