You don't need to be a doctor today to that ... just call yourself a 'Faith Healer', 'Shaman' or 'Medicine Person' ... don't need no fancy institution or organization to get those credentials.
I'm Indigenous in Canada and human gullibility, taking advantage of people and charlatanism is not something that Indigenous people are immune to .... we have our problems with nutjobs who pretend they are more powerful than anyone else for one reason or another. We have our religious leaders who think they have more power than anyone else just because they want to.
I once met a traditional 'Shaman' at a Pow Wow who did a whole ceremony in front of people telling them how great he was and how his brews, herbs and remedies and chants and singing could cure anything .... he even claimed he could cure cancer. I talked to him for a while and you'd think he was genuine but when it came to receiving his medicine bundle I asked him how much and he said 'how much is your health worth to you?' .... I immediately thought that was a fantastic sales pitch, gave him $20 and told everyone I met that he was just another fraud. A day later he appeared in the local paper saying he had healed a woman with cancer .... the woman died a few months later and we never heard from this faith healer again.