You will receive your Twilio account from DCOMM once your use-case is approved. You can begin your request in LiftCap.
While support is always improving, Twilio SMS or IVR services will not always support all elements of your survey design. Always test before going into Production!
You can only use a Twilio number in one REDCap project at a time. If you need to use Twilio in simultaneous projects you will need to secure multiple Twilio numbers from DCOMM.