Select the 2 tokens you want to swap. (Keep in mind tBTC is not an OP_20 token, tbTC <> OP_20 swaps are NativeSwaps)
Once you've selected your 2 tokens to swap, you can either enter the amount you wish to sell (token on top), or the amount of the token you want to buy (token on the bottom).
Swap Settings
On the top right of the swap section, you will see a cog icon, which will open the swap settings modal. Here you can select your:
Max slippage
Mining fee rate
Priority fee
The default values should be acceptable for most cases.
Swapping
After inputting your desired amounts and configuring the settings, click the swap button.
You will be quoted again for your swap, once confirmed, clicked "Swap Tokens".
Sign the transaction in your wallet and, congratulations! You've swapped.