Fatal error: Uncaught Error: Interface 'Google\Auth\ExternalAccountCredentialSourceInterface' not found in C:\xampp7\htdocs\sigpkl\vendor\google\auth\src\CredentialSource\FileSource.php:27 Stack trace: #0 {main} thrown in C:\xampp7\htdocs\sigpkl\vendor\google\auth\src\CredentialSource\FileSource.php on line 27