One of ButterSwap's farms uses BUT-USDT liquidity provider tokens to farm. So first, you need to own BUT tokens.
BUT is the official platform token for the BitUp project (https://bitup.com/), which was established in 2017 and invested by Huobi Group. It is listed on Huobi Global, BHEX, etc.
You can buy BUT in Huobi using BTC/ETH, or in BHEX using USDT. Simply searching "BUT" in Huobi/BHEX, and you will find BUT to buy.
Withdraw BUT from Huobi/BHEX using Heco address to your Heco wallet. Then follow the steps in 💰 How to use ButterSwap? to participate in farming. Basically, you need to provide BUT-USDT in liquidity pool and use the obtained LP tokens to stake in farm pools.