I already tried it also requested for Ethereum not usdt are you sure you can use usdt instead of Ethereum
I meant on cowswap you pay gas fee from token you are swapping from. In your case, it will be usdt. I tested myself just now, and didn't have any eth on my wallet, yet I could trade by paying gas in token I was swapping from.
https://www.talkimg.com/image/kuUC3I already tried it also requested for Ethereum not usdt are you sure you can use usdt instead of Ethereum
They asked ETH for gas if it's your first time,
However, they still needed to pay gas fees (in ETH) to execute approval transactions the first time they wanted to trade any token.
furthermore I doubt they don't ask for gas at all because moving tokens should somehow incentivize network validators. Tbh I haven't followed the development of the ETH protocol for a long time, I think they have now implemented their capabilities a kind of CPFP in bitcoin.
I have traded on cowswap before, but traded $SAIL for first time today, gas fee was paid in token itself, had no $ETH in my wallet.