I would recommend to check out SHKeeper. It's a unique combination of gateway and merchant. It lets you directly accept payments in multiple cryptocurrencies, without fees or intermediaries.
It supports BTC, ETH, LTC, DOGE, XMR, XRP, TRX, BNB, MATIC, AVAX, USDT (ERC20, TRC20, BEP-20, Polygon, Avalanche), and USDC (ERC20, TRC20, BEP-20, Polygon, Avalanche). Super flexible and worth a look if you're into crypto.