Fatal error: Uncaught Error: Class 'League\OAuth2\Server\Grant\AbstractGrant' not found in /mnt/volume_lon1_01/backend/admin/vendor/league/oauth2-server/src/Grant/ClientCredentialsGrant.php:23 Stack trace: #0 {main} thrown in /mnt/volume_lon1_01/backend/admin/vendor/league/oauth2-server/src/Grant/ClientCredentialsGrant.php on line 23