21608: The 'to' phone number provided is not yet verified for this account.

You have attempted to send a message to an unverified phone number while using a trial account.

To prevent spam, trial accounts can only send messages to phone numbers you've verified with Twilio. You must upgrade your account to remove this restriction.

You attempted to send a message to a phone number that has not been verified on your trial account.

• Verify the phone number you wish to reach via the Twilio Console. See Verified recipients for details on trial verification limits. Note that you will need access to this device to receive the call or text with your verification code.
• Upgrade your account to remove this restriction.