There are dozena of banks in khartoum. I am a user of bank of khartoum. The think is their financial infrustructure doesnt allow you to buy cryptos from popular crypto exchange sites like binance and coinbase. To solve this problem all I do is withdraw cash money from my account, send this money to my friend in kenya on black market, then he buy bitcoin and transefer to my okx bitcoin wallet. If I need to sell my bitcoin there is no problem I sell it and they transfer to my bank account directly it takes 24hrs. Its complicated process. I hope this helps. If you have other Ideas lets talk.