Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Recipient's phone number. Must be in E.164 format
"+1234567890"
The text message to send
"Hello, world!"
If you lease a phone number from Contiguity, you can use a specific one by providing it here.
"+15555555555"
Attachments to send. Must be HTTPS-secured URLs with file extensions. Max 3 attachments, 5MB cumulative size.
3["https://example.com/image.png"]