Fatal error: Uncaught TypeError: join(): Argument #2 ($array) must be of type ?array, string given in /home/ondemand/test.ondemandpro.net/php-docs-samples/appengine/php72/grpc/index.php:11 Stack trace: #0 /home/ondemand/test.ondemandpro.net/php-docs-samples/appengine/php72/grpc/index.php(11): join(Array, '|') #1 {main} thrown in /home/ondemand/test.ondemandpro.net/php-docs-samples/appengine/php72/grpc/index.php on line 11