You have a little bug.
So i sent the coins to mjG1DgeypYCnBXCg2eeWs8qR4FTRQiVoH6, got the 3 min of credit.
Hit call button without entering a number, was asked to use my mic and it said call connected. Timmer starting ticking and taking away credit.
Might want to code in that will not connect unless a phone number is entered.