The liquidity provision of an option is similar to that you provide liquidity on Uniswap. Before you provide liquidity, you need to have tokens to provide liquidity. You can access tokens through option generation or market purchase from the swap interface. Once you are prepared, you can provide liquidity through the following steps:
Visit option trading and pick the option that you want to provide liquidity for. Click "Trade" to enter into the dedicated page for the option you choose.
Once you enter into the page, click liquidity and you will see the the liquidity page. You can add or remove liquidity on the left hand side and see statistics of total liquidity and your provided liquidity on the right hand side.
A detailed explainnation on the liquidity provision mechanism can be found here: