According to the SketchUp Help Center section on Customizing Toolbars and Menus, in Windows there should be the option to Show shortcut keys in ScreenTips.
What version of SketchUp are you using? Your profile indicates a version that does not exist.
Where did you get that window shown in your screenshot? It’s a window from LayOut and has nothing to do with SketchUp. this is what it looks like in LayOut 2024.
Yes, I now see where it says Layout in the corner of the screen.
The question still remains, how can I add shortcut key letters to the ScreenTips in SketchUp 2024? I don’t have the shortcut keys memorized and it would be helpful to have them on the ScreenTips.