@mojofrododojo@lemmy.world is right. Go to any moderate-sized market in Africa and if you just show up wit USD or GBP or EUR, someone will gladly exchange it for local currency. Not at the bank rate, just whatever they feel like. It's a 20 minute conversation.
"OK, Mister Watto - who does currency exchange in this truck stop town?"
"Eeehh, talk to Martin down at the cantina."