Problems with Twilio

Hi,
I have a few problems when I set my Twilio Account.
For now I am testing the service with a free account.
I’ve set the field related with my Twilio account with all the data required, but when I try to book a service with another that is not my thelephone number, the system send a sms at my thelephone number but I need that he sms must be send at the telephone number that I used for book the appointment.

How can I solve that?

Thank you in advance

Mattia

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