App window won't move

I have no idea how it happened, but an app window is too high on the screen. I can't get it to move lower in the screen. So, I can't access the options on the top menu bar of that app. How do I get to it? I tried hiding the desktop menu to get at it, but that's not high enough. It's off the top off the screen. I'm attaching a screenshot to show what I mean. Thank you!