Currently, there are not many countries that allow bitcoin as a payment method, I only know that El Salvador is a pioneer in accepting bitcoin as a means of payment.
I'm not sure how many countries explicitly allow Bitcoin for payment, but tons of digital stores accept Bitcoin. I'd assume the country they're based in at least doesn't punish them for accepting BTC or allowing people to buy stuff with BTC. One digital store that I regularly visit is based in Singapore and they've been accepting Bitcoin for years now. It's not exclusive to them either. I believe that's no surprise considering how many payment providers are available on the market nowadays. I think you'll be able to find other examples if you want to pay with BTC. It just takes a bit of time to look around. CMIIW.
Even In Nigeria where bitcoin and all forms of cryptocurrency trading is banned, some services and stores still on their own accept bitcoin as payment for their services or goods, though they usually will not make any sign available to customers that they accept bitcoin payment, acceptance is simply based on the customer's request, and for some of this stores or services to agree they accept bitcoin payment, you have to be a customer they have known for a while, this i believe is a nothing but a precautionary measure they've put in place to help them not make the mistake of accepting bitcoin payment from a government agent mistaking him or her for a true customer.
Overall, bitcoin is accepted in several parts of the world, regardless of regulations and bans, but personally, I still prefer to spend fiat than spend bitcoin on goods or services.