BTC is not a smart contract dapps platform, so it can't have DEX like Uniswap. BTC is simply a currency on which you can send/receive coins. It's simple yet robust. If you want smart contract capability, IIRC I've read somewhere that tokens exist on BTC forks, both BCH and BSV. They may tweak the code so its chain can support smart contracts, thus support DeFi and stuff. However, if you still want to use "BTC" but in DeFi environment, you can use wBTC and stuff.