Ringcentral and Salesforce Flow Action for SMS

the ringcentral and salesforce app integration made an update recently to add a Send SMS action to salesforce Flows. I was very excited but upon first using it, I learned we have to setup an auth provider and named credential. not a big deal but frustrating that there is no documentation that this is necessary. importantly though, once i did set it up, im getting this error:

An Apex error occurred: rcsfl.RingCentralSendSMSAction.FlowActionException: [RC-104] A2P SMS API error. HTTP 403: {"errorCode":"MSG-242","message":"","errors":[{"errorCode":"MSG-242","message":""}]}

which appears to indicate that the number ive chosen is not configured for P2P messaging, only A2P since its registered with our TCR campaign. HOWEVER there is no legal way to send SMS without registering with TCR. but the endpoint used by the ringcentral managed package specifically only applies to P2P capable phone numbers. Correct me please if i’m wrong on this, but its very frustrating to have a new powerful feature like this delivered NOT in beta, and it be so fundamentally unusable. if anybody has solutions, please share them. I know that i can build my own apex but that takes development and deployment time that i would prefer to avoid.