Error 21216
Product: Programmable Voice
ERROR - 21216
API: Call blocked by Twilio blocklist
The destination number is blocked by Twilio because it either has a high-risk of fraud or, for regulatory reasons, cannot be enabled by default.
If you have a legitimate need to call this number, please email help@twilio.com with an explanation of your use case.
Possible Causes
The phone number dialed is on the Twilio blocklist
Possible Solutions
Change the number dialed or reach out to Twilio for an exception