57022: Required header is missing or invalid

Twilio Messaging returns This error when a request is missing a required header or includes a header with an invalid value. This error is listed as a Messaging error in the Error and Warning Dictionary.

• One or more mandatory headers are missing from the request.
• A required header is present, but the value is invalid.

• Add every mandatory header required by the request.
• Check the error logs to review the exact error, potential causes, suggested solutions, and the full HTTP request and response associated with the request.

• Debugging Your Twilio Application
• Messages resource