There are a few options here when wanting to create a note that isn't meant to be billed.
A progress note can be created without being tied to an appointment. This can be created by going into the client's case and adding a new progress note.
Additionally, a service type is not required when creating an appointment. This means the progress note can still be tied to the appointment, but an invoice cannot be created.
If there's different functionality you're looking for, please resubmit your idea with additional details for us to review! Thank you!