Add Custom Action to Rails Admin

There seems to be very poor Rails admin documentation. All I can find is this link https://github.com/sferik/rails_admin/wiki/Custom-action

But no, no matter where mentioned in this link, how to use a custom action, and the views for it in rails admin install only the plugin, which is what is next. I don’t have enough time to even look at the rails admin code and figure out how to do it.

Here I want the screenshot to link to here