When trusting an authority, it is expected the authority is an expert in the field. when an individual is arguing about treatment of an illness, but does not have a degree in the medical field, this is a case of which logical fallacy?

If a person do not have any sort of degree in the medical field but still having an argument about the treatment that is being given to the medical condition, it would definitely lack logic and this case of logical fallacy is called as False Authority. In today's world where everything is about the personality credibility, we see a lot of people with this fallacy.