how to take a screen shot
Screenshots on a Mac:
To take a screenshot of the entire screen, press Shift-Command-3. To take a screenshot of part of the screen, press Shift-Command-4 and then drag the cursor to outline the area you want to capture. If you want to capture a specific window, press Shift-Command-4. Hit the spacebar.
Screenshot on Windows computer: To take a screenshot of your screen, press Ctrl + PrtScn keys.
There are also softwares which you can download that make screenshotting your screen easier.
Hope I helped!
Hi Mkora, Could you try the instructions in the following article, and see if they help: Take screenshots on Firefox