The panel does not tell you a fixed minimum trade size, but you must keep some of the chain's native coin for the network fee. The panel's Max button already leaves a reserve: about 0.005 SOL on Solana, 0.0005 BNB on BNB Chain and 0.0002 ETH on Robinhood Chain.
If you try to spend more, the panel says you do not have enough and shows how much you can use. Very small trades can also be eaten by network fees, so check the quote.