Bitcoin is a digital currency that circulates freely, without any control or supervision from banks, governments, or anyone else. In contrast, bitcoin relies solely on cryptography and software between computers.
what if the government closes or does not allow the exchange of Bitcoin or cryptocurrencies with the official currency in each country?

this really doesn't worry me because if the government bans transactions, BTC can still do P2P transactions without going through government control, really this is the real value of BTC, in essence BTC is a decentralized currency and no one can control every transaction of BTC, your problems are sure we have specific solutions.