Any elected official compelling you to wear a mask should be arrested and jailed for medical malpractice.
Until that happens, print, cut to size and laminate (optional) this card to present to the employee or manager or owner of a business (if confronted) and simply telling them you have a medical condition that prevents you from wearing a mask. Offer the card if simply stating you have a medical condition doesn't suffice. Don't offer up your medical condition. It's illegal for them to ask for it under ADA and HIPAA.
https://i.pinimg.com/564x/88/11/31/881131b584efccae8a74f6fe25c2739e.jpg
I have plans for a new calling card based upon Paladin's stating “Have Gun Will Shop” but we are not quite far enough down the tyranny road yet.
Thank you