screen shot on mac

You must have misread it, or there is a problem with your keyboard not recognizing key presses. Here is the specific article for the older Monterey OS and it is the same for Ventura.

Take screenshots or screen recordings on Mac - Apple Support

Capture the entire screen - Press Shift-Command-3.

Capture a portion of the screen - Press Shift-Command-4, then move the crosshair pointer to where you want to start the screenshot. Press the mouse or trackpad button, drag over the area you want to capture, then release the mouse or trackpad button.

Here is more information about Keyboard shortcuts for Monterey:

Use macOS keyboard shortcuts - Apple Support

Also, you can check if you have a conflicting Keyboard Shortcut:

Change a conflicting keyboard shortcut on Mac - Apple Support