A prerequisite for a connection with a doctor is that you have already had an appointment with the medical practice, or that you are registered as a Multimed patient for that doctor. It is possible to connect to more that one doctor.
All doctors whose systems are connected to Well can be recognised by a corresponding symbol. If the symbol is greyed out, the doctor is using a software that only supports Multimed patients who are insured with a different insurance company or under a different model than the one you specified.