Good Afternoon,

My goal is to send an SMS message using the API to a user inside our recently created sandbox environment and I have already added a couple of phone numbers for users. However, when I tried to send an SMS message using the interactive API, I will get the error code MSG-242 "The requested feature is not available".

I have tried this using the sandbox's main number and other phone numbers that I have assigned to users. They are also listed as valid numbers when I call the api for phone numbers ( /restapi/v1.0/account/{accountId}/phone-number ).

I have also tried to use RingCentral on my Desktop and sending a message in the sandbox environment. This results in "Your extension does not support external text messaging. Please contact your account administrator".

Calling the Get Extension Phone Number List API ( /restapi/v1.0/account/{accountId}/extension/{extensionId}/phone-number ) shows that every account only has CallerID under the "features" section.

I have also given the SMS permission to the app.

How would I fix this?