If it does, how is it done? If it doesn't, why not. I have some BTC to exchange for NGN. Can I be guided?
Simply search for P2P in YouTube and you will get all the information you need, from creating your account, KYC, deposit, exchange from one currency to the other and including the P2P features you seek. P2P works perfectly well for converting cryptocurrency to fiat and vice versa and its exclusively done in exchanges... the safer place for that, for security reasons. However you must know that the Nigerian government of the day have not been too friendly with exchanges, hence the reason many exchanges stopped allowing trade in the Nigerian Naira(NGN). Prior to the fight against exchanges, Binance and Kucoin were the biggest platform for P2P trades in Nigeria but they have been forced to close that services for Nigerians. There are still few exchanges where that is done now.