How to remove this button from the title bar?

[SadSock]

There is a button on the title bar that I'd like to remove. I know Firefox allows removing this title bar buttons—can this be implemented here as well?

[CutterKnife]

The latest version of Firefox allows this button to be removed.
Since Floorp 12, which is under development with the goal of releasing the Stable version by this summer, is based on the Firefox Rapid Release, this problem will be resolved.