Use gnome-screenshot
The first most important way of taking screenshots in Linux is by using Tools that can give flexibility with respect to editing the captured screenshot among other benefits. When one is looking for a tool in Linux to do such a job, the Gnome-screenshot comes into play. Gnome-screenshot utility is part of the GNOME Desktop Environment, which can also be used to take screenshot. It also has a command line mode (gnome-screenshot)Use gnome-screenshot Command line
This utility has much more features as well as flexibility when taking screenshots and is included in some linux distributions by default. However if your linux operating system does not come pre-installed the here is how to install it.
https://allguideto.blogspot.com/2018/02/how-to-take-screenshot-in-linux.html