How to toggle the Browser Manager Sidebar on button press?

[Test-Account666]

I like the browser manager sidebar, but it is also kinda annoying when I don't need it.

I'd like to have a way to toggle it. I know there's custom actions, but I don't know how to set these up.

This is the sidebar I'm talking about btw:

[breadbeforerice]

#556 #discussionComment-7465366 Used based on this. However, if this setting alone is opened and closed, the lower part is sloppy and on the way.