This is not unturned related.
I wanted to buy some games on steam because I had birthday like a week ago but I can’t buy anything from a wallet like qiwi PayPal etc. because steam decided to cut from Russia for some reason (probably bc US and Europe hating on Russia).
AFAIK Steam hasn’t taken any independent actions that affect Russian players. You should contact Steam Support for assistance regarding Steam features such as your Steam Wallet.
I’d imagine that your issues could be related to the reason Ukrainian, Russian, and Belarusian developers/publishers are not receiving payment right now—the bank service used for that region has complicated the payment process (presumably due to sanctions).
Alternatively, it’s quite likely that various payment processing services (e.g., PayPal) have suspended services in regions such as Russia (or out of Russia), which would thus prevent you from using that for Steam purchases (and any sort of purchase).
Due to the invasion a decent chunk of payment processors are not doing business with Russia and associated territories. I am not going to help you circumvent that, but I am going to tell you that you still have options.