Until now, there is no country officially accepted crypto for trading or purchase as I know. Can you explain why?
You may not know which countries around the world use crypto currencies. But you can see details about EL Salvador. Where cryptocurrency has been officially adopted and various products and transactions have been launched by crypto currency.
https://bitcointalk.org/index.php?topic=5342087.0Moreover, do you think that which country could be the first?
But as far as I know, the first Bitcoin was officially recognized by the government of El Salvador. But many countries around the world have already started Bitcoin trading and they do full transactions with Bitcoin just for the convenience of using Bitcoin.