DEXs are getting more and more popular due to the fact that we do not need to do a full blown KYC. Appart from DyDx .. here is another one which seems to be coming up and is still under beta tests.
ANTARTIC Exchange -->
https://partner.antarctic.live/en-US/testnet?invitationCode=yLKcpFnL
Give it a go .. you can connect with your metamask and then goto the faucet and request for 5,000 USDT and also gas fee to take the exchange for a spin. There would also be some airdrops. I've just started playing with it for a few days and looks really interesting.
Nothing better then to trade with some free airdops.