I'm trying to test sending an SMS from the sandbox with phone number "16502420326" (sandbox phone number), but I am getting the following error:

Failed to send message: Client error: `POST https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension/~/sms` resulted in a `403 Forbidden` response:

{

"errorCode" : "FeatureNotAvailable",

"message" : "The requested feature is not available",

"errors" : [ {

"e (truncated...)

I've read in other questions posted by members of the community that the sandbox phone number needs to be enabled from RingCentral end in order to test SMS functionality.

Could someone please enable SMS for my account? Thanks!