In America, hypnosis is an unregulated profession and there is no accreditation.
I read an article by a hypnotherapy school that said, “You don’t need a license, you just need to meet certain criteria.” There is NO criteria!
Only three States require registration, but anybody can do that as long as you pay the fee.
Similar in the UK, there are many “accredited” schools, and also an abundance of minefields to go through to find a course that meets your needs. If you can pay, you can take a course!
Your best alternative is to go through a professional organization.
Here are three I would suggest:
Society for Clinical and Experimental Hypnosis www.sceh.us
American Society of Clinical Hypnosis www.asch.net
American Board of Medical Hypnosis
Also, look into: Hypnosis/Dental Hypnosis/Psychological Hypnosis and Social Work Hypnosis/Nursing
If you want to learn hypnosis, find like-minded minded people. Facebook has an abundance of forums you can join. Get involved with Skype/Zoom practical sessions and read! The only way to become good at hypnosis is by doing it. Once you become proficient, then decide if a course is worth the investment. So many are padded with irrelevant information and redundant techniques. KIS (Keep It Simple).