My sandbox account phone # is +19295755523. When I try to send an SMS message, I get the following response:

"errorCode" : "FeatureNotAvailable",

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

"errors" : [ {

"errorCode" : "MSG-242",

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

From other posts that I see here, it looks like someone at RingCentral has to enable that feature. Can someone please do that for me? Or let me know if there is something else I have to do? Thanks.