Problems Running MongoDB\Collection::mapReduce()

Recently, I have been worrying a lot about MongoDB's environment.
Environment:
·MongoDB Server 3.2.0
　(*Created database using MongoDB API in Microsoft Azure's CosmosDB)
·mongo_php_driver 1.4.3
·mongo_php_library 1.3.2
·PHP 5.6.35
Purpose:
·I would like to run MongoDB\Collection::mapReduce().
Problem:
·Exception 'MongoDB\Driver\Exception\RuntimeException' with message 'Command is not supported'