There is a (top-right) hot corner action set up by default, that shows previews of all open windows. I can find it under Settings > Desktop behaviour > Screen edges, and then the top-right edge is linked to an action, and it's called "Present windows - All desktops".
But that subcategory in settings doesn't have an option to assign a keyboard shortcut to it; And under the category for "Shortcuts", there is no option that has the words "windows" or "desktops"...
So would it be possible to assign a keyboard shortcut, such as Super+Tab, to do what the top-right hot corner does, which is show all my open windows? And if so, how?
Do the following images help?
Ensure "Present Windows" is active:
Set a shortcut of your choice or use the suggested default (Ctrl+F10):