The app has been created from scratch on facebook, url is ok as I could login the 1st time to push on allow and after that I get a 404.
Tried multiple times to connect with facebook and always get 404.
Checking the php logs I see the following:
PHP Warning: Declaration of JofacebookgalleryControllerAccount::save() should be compatible with Joomla\CMS\MVC\Controller\FormController::save($key = NULL, $urlVar = NULL) in /var/web/XXXX/public_html/administrator/components/com_jofacebookgallery/controllers/account.php on line 20