You should use the Win+PrtScrn shortcut to capture the entire screen and the Alt+PrtScrn key combination to take screenshots ...
The app hosted at excalidraw.com is a minimal showcase of what you can build with Excalidraw. Its source code is part of this repository as well, and the app features: 📡 PWA support (works offline).
If you take a lot of screenshots on Windows 11, ShareX is the tool you should be using, and here are a few reasons why.