Have not been in the situation yet, but in my country you can be exempted for medical reasons. The barkeep, hairdresser etc. has to ask for a corona passport (which indicates vaxxed, immune or recently testeds). This of course is pure fascism, but they are fined hefty fees if they let you in anyways, except if you say the magic words: "I'm exempt". Then they are absolved. They are not allowed to ask for the medical reason and you don't need a doctor's slip. They can probably say you may not enter, but some say we can then sue them for unequal treatment. I think you have something similar in America?

It's still theory, since it has to my knowledge not been challenged yet. People are so gullible and follow whatever our dictator says. :-(

I am going to try the "I'm exempt" approach. If that fails, then I think I am going to start wearing the yellow star.