Warning: Unsupported declare 'strict_types' in /var/www/html/push-notification-service-v2/vendor/kreait/firebase-php/src/Firebase/Database/Snapshot.php on line 3

Parse error: syntax error, unexpected ':', expecting ';' or '{' in /var/www/html/push-notification-service-v2/vendor/kreait/firebase-php/src/Firebase/Database/Snapshot.php on line 53