With auto-queen enabled, every time you move a pawn to the final rank, it will automatically promote to a queen. This can save valuable seconds in a bullet game!

You can find the option in your settings, under 'live chess' settings. Click on the 'Play' tab to see the option near the top of the list.

On the browser it is called 'always promote to queen' but in the app it is called 'auto-queen.' These both have the same effect.

Once you've turned on the option, the next time you promote a pawn you won't get the popup menu asking you which piece you want to promote to, it will automatically become a queen.

However, if you run into a situation where you need to under-promote, you can hold ALT while you move the pawn to promote, and the menu will appear, same as normal.