Basically all VoIP services do not support SMS as they are based on land-line, not mobile numbers. The people behind the https://www.satellite.me/ app have a long story to tell about how anti-competitive the established mobile carriers are in that regard as they know full well that their numbers and SMS verification codes are about the last moat they have to vendor-lock their users.
So yes, a dedicated SMS service like Twilio is more or less your only option I think.