I am setting up SNS to be able to send text messages to myself from Lambda. I am trying to add a (USA) phone number to SNS Sandbox, and I am getting the following message:
An error occurred while attempting to add a phone number to the SMS sandbox. The phone number was not added.
Error code: UserError - Error message: No origination entities available to send
What exactly does this mean and how can I resolve this? I looked up the error message and found nothing similar.