Cognito user verification via SNS stopped working?

Some time back, AWS started restricting the SMSs sent from SNS service. The restriction is for senders without any Origination IDs aka long code (phone number) or short code. This is basically to stop spammers.

If user verification from Cognito was working before, and it does not now, the reason would be this.

You would see this error in the logs.

For this, you would need to get an Origination ID from AWS Pinpoint.

which takes you here

From there, go to request phone number using this form

This would cost $2/month.

Once this is set up, the verify code should start coming.