Exception: Unauthorized for this grant type SDK HTTP Error at https://platform.devtest.ringcentral.com/restapi/oauth/token Response text: { "error" : "unauthorized_client", "error_description" : "Unauthorized for this grant type" } Previous: Response has unsuccessful status #0 phar:///home4/crownfoo/public_html/foodondeal/ringcentral/demo/ringcentral.phar/ringcentral/ringcentral-php/src/Platform/Platform.php(214): RingCentralSDKHttpClient->send(Object(RingCentralPsr7Request)) #1 phar:///home4/crownfoo/public_html/foodondeal/ringcentral/demo/ringcentral.phar/ringcentral/ringcentral-php/src/Platform/Platform.php(301): RingCentralSDKPlatformPlatform->sendRequest(Object(RingCentralPsr7Request), Array) #2 phar:///home4/crownfoo/public_html/foodondeal/ringcentral/demo/ringcentral.phar/ringcentral/ringcentral-php/src/Platform/Platform.php(123): RingCentralSDKPlatformPlatform->requestToken('/restapi/oauth/...', Array) #3 /home4/crownfoo/public_html/foodondeal/ringcentral/demo/sms.php(20): RingCentralSDKPlatformPlatform->login