It will not be advisable to make transactions in bitcoin within a country where cryptocurrency transactions are illegal by the law. But Imagine this scenario that someone has been using their bitcoins for transaction secretly successfully, and then one day decides to use the bitcoin that they have to make payment for something like a property to the owner of the property, If there is this kind of problem for instance where the owner of the property decides to claim that they did not receive any money in bitcoin, and the case is taken to a law court, what do you think the outcome of the case will be?
If proofs of payment are provided but in cryptocurrency, do you think the court will consider it even though transactions are tagged illegal with it? or will the case be thrown out and the owner of the property with the false claim of not receiving the money be allowed to go freely?
For someone who has been using it and hiding it perfectly, I don't get why that person would pay up with crypto?
If crypto or Bitcoin is illegal in their country then both buyer and seller would surely face the charge.
The person who has been using Bitcoin or crypto in that country would surely knows a way to convert it into cash, so why would that person even need to pay with crypto?