21671: Content Templates are not supported for messaging in this Twilio region.

This error occurs when you create a message with a Content Template in the Ireland (IE1) region. IE1 does not support sending Content Template messages.

• You included the ContentSid parameter when you created a Message in IE1.
• You included the ContentVariables parameter when you created a Message in IE1.

• Remove ContentSid and ContentVariables from the request and create the message with the Body parameter instead.
• Use the United States (US1) region to send Content Template messages.

• Messaging features in Ireland (IE1)
• Use the Programmable Messaging API with Twilio Regions
• Message resource