If you find that after entering a phone number the machine stays on the 'One moment' screen and does not send an SMS, then the Twilio settings below ought to be checked:
From and To numbers
In the Twilio panel of the Admin, both the From and To numbers must be filled in (along with the other panel credentials.)
The From number is that which you reserved from Twilio. It is not the greyed-out sample number that is shown in the admin to demonstrate formatting.
The To number is your personal number at which you'd receive operational notifications about the machine. If you have notifications disabled, this number must still be provided (even though it's not being sent to.)
Phone number formatting
The From and To numbers must be formatted correctly in international dialing format.
For example, if you have a Canadian number (403) 867-5309, then it ought to be entered as +14038675309
From number is capable of SMS
Some numbers from Twilio do not offer SMS services, but rather calling. Log into Twilio, view the 'Manage Numbers' page, and verify whether your chosen number is SMS-capable under 'Capabilities'.
If you continue to experience difficulties, please submit a support request.