You can't on limit trades, but you can on stop market trades. Because trading liquidity on Kucoin is also quite high in my opinion, placing an order on a stop market will not have a significant price difference from the target price you set compared to a regular limit order.
I think OP isn't talking about limit price or market price. It's about how much USDT he want to place to buy Bitcoin. On the Binance he can decide how much USDT wants to book. Because the total showing in Binance in USDT. So whether you can book order by calculating BTC or you can book an order by calculating USDT. Then Binance will calculate automatically opposite. That's what OP asking I am guessing.
Simply KuCoin does not have this feature. So you can't do it. You have to calculate manually or any other way.