How can I make the window fully accessible?

Question

Mozilla Firefox

When you want to share something from some site on Facebook, a corresponding window appears, there is what you share, a field for your comment and a couple of buttons at the bottom. So I have these buttons go below the taskbar. These windows do not have scrollbars. To get to them, I have to set the panel to go down. Pushing the window up with the mouse does not work. Reducing the size above and on the side does nothing, the lower part remains where it was.
What are these windows called? Is there any way to adjust their size and position on the screen?
On the advice of one of the users, I downloaded the Taekwindow program, which gives you more sophisticated options for moving windows. With her help, the problem is solved.