After spending at least an hour researching every screenshot option for Ubuntu Linux 18.0.4 64 bit, using gnome desktop. I've decided to ask here. I can take a screenshot using PRTSCN only but no other options work and no video options work. I'd even like to install a special app and use the keyboard settings to assign a keyboard short cut to the app.
Here's the list of supposed actions. Only the top one works for me which are saved under home/my-name/pictures PrtSc – Save a screenshot of the entire screen to the “Pictures” directory. Shift + PrtSc – Save a screenshot of a specific region to Pictures. Alt + PrtSc – Save a screenshot of the current window to Pictures. Ctrl + PrtSc – Copy the screenshot of the entire screen to the clipboard. Shift + Ctrl + PrtSc – Copy the screenshot of a specific region to the clipboard. Ctrl + Alt + PrtSc – Copy the screenshot of the current window to the clipboard