4007: Template not sendable.
The template cannot be sent as addressed.
HTTP status: 422.
The named template is not approved, its parameters do not match its published schema, or a parameter cannot be addressed by name. Nothing was sent.
Troubleshooting
Section titled “Troubleshooting”- Read the template with GET /v1/templates to confirm its status and send_schema; details[].param names the discriminating field.