tasplanning_report/public/oauth_start.php

<?php
require __DIR__ . '/vendor/autoload.php';

use Google\Client;

$client = new Client();
$client->setAuthConfig('/var/www/secure/oauth-client.json'); // OAuth client
$client->setRedirectUri('https://llm.modulos.com.au/oauth_callback.php');
$client->setAccessType('offline');              // get refresh token
$client->setPrompt('consent');                  // force to ensure refresh token
$client->setScopes([
  Google\Service\Drive::DRIVE,
  Google\Service\Docs::DOCUMENTS
]);

header('Location: ' . $client->createAuthUrl());