PrestaShop 403 error on indexing api

A 403 error on an Indexing API usually means permission denied or authentication issue.
For Google Indexing API, common reasons are:

Common Causes of 403 Error

1. Service Account not added
   • Add your Google Cloud service account email as Owner in:
     • Google Search Console
   • Use the exact service account email ending with:
     xxxxx@xxxxx.iam.gserviceaccount.com
2. Indexing API not enabled
   • In Google Cloud Console:
     • APIs & Services → Library
     • Enable:
       • Indexing API
3. Wrong API Scope
   Use this scope:

   https://www.googleapis.com/auth/indexing
   

4. Website not verified
   • Your site must be verified in:
     • Google Search Console
5. Using Indexing API for unsupported pages
   Google officially allows Indexing API mainly for:
   • Job Posting pages
   • Live Stream pages

   Normal blog/product pages may return errors or limited success.

6. JSON Key issue
   • Make sure the downloaded JSON credentials file is correct and active.
7. Wrong endpoint
   Correct endpoint:

   https://indexing.googleapis.com/v3/urlNotifications:publish
   

Example PHP Request

$client = new Google_Client();
$client->setAuthConfig('service-account.json');
$client->addScope('https://www.googleapis.com/auth/indexing');

$httpClient = $client->authorize();

$response = $httpClient->post(
    'https://indexing.googleapis.com/v3/urlNotifications:publish',
    [
        'json' => [
            'url' => 'https://example.com/page-url',
            'type' => 'URL_UPDATED'
        ]
    ]
);

echo $response->getBody();