What does the VARTA error `caller_id_not_on_trunk` mean?

HTTP status: 400  ·  Type: invalid_request_error

What it means

The from number you asked to dial with is not one of the trunk's registered numbers.

What causes it

Raised when the requested caller id isn't in the trunk's registered numbers (backend/app/services/telephony.py), reached from POST /v1/calls with dial: true.

What to do

Omit from to use the trunk's default number, or register the number on the trunk first.