in chime-sdk-signaling-cpp/src/signaling/default_signaling_client.cc [41:47]
void AddAttendee(InternalStreamConfiguration& internal_stream_configuration,
const SignalingClientConfiguration& signaling_configuration) {
internal_stream_configuration.attendee.attendee_id =
signaling_configuration.meeting_configuration.credentials.attendee_id;
internal_stream_configuration.attendee.external_user_id =
signaling_configuration.meeting_configuration.credentials.external_user_id;
}