The list of ad groups for the advertisers with the id specified in the URL,
filtered by campaign id if provided

Bad Request. Indicates that the server cannot process the request due to client-side error.
For example invalid input.

Unauthorized. The API key is invalid and needs to be re-generated.

Forbidden. The token passed in has been successfully authenticated,
but can’t perform the given action due to not having sufficient permissions.

Internal server error.

The server is temporarily unable to handle the request due to maintenance or overload.