I've integrated with Twilio. I pay a whole bunch of money every month for sending SMSs. And then recently they made me jump through a bunch of regulation hoops. Had to give them all my business documents.
So even if OP does all the work of integrating it, I assume OP isn't going to pay the fees for you, so then you have to create your own Twilio account and jump through the same hoops.
I've integrated with Twilio. I pay a whole bunch of money every month for sending SMSs. And then recently they made me jump through a bunch of regulation hoops. Had to give them all my business documents.
So even if OP does all the work of integrating it, I assume OP isn't going to pay the fees for you, so then you have to create your own Twilio account and jump through the same hoops.