Twilio :(Error: 63015) Channel Sandbox can only send messages to phone numbers that have joined the Sandbox.
How can I send a message to a recipient without adding them to sandbox?
Twilio :(Error: 63015) Channel Sandbox can only send messages to phone numbers that have joined the Sandbox.
How can I send a message to a recipient without adding them to sandbox?
They must have joined the sandbox unless you apply and are approved for your own WhatsApp number, detailed below.
How Can I Get my Own WhatsApp Twilio Number for Use in Production?