How Do You Tell if a Hair Transplant Clinic Is Legit?

I'm currently researching hair transplant clinics and trying to figure out what signs show that a clinic is reliable.

There are so many options online, and it's not always easy to tell the difference between a good clinic and one that just has strong marketing. I've been looking into things like patient results, reviews, clinic information, and different treatment methods.

What are the main things you look for before trusting a hair transplant clinic?