One of possible solution to create screenshots under wayland without terminal session

[Engimono]

possible smooth solution:

1. install xdotool: sudo apt install xdotool
2. create a custom shortcut (as an example Super+Print) with the command: xdotool exec flameshot gui

As a result, it loads "flameshot gui" without creating a terminal session that could appear in front of the screen's part you want to take as a screenshot.

[LiangART]

Your solution is really awesome!!! No one has adopted it? This is the simplest setup solution

[mmahmoudian]

@Engimono
I don't understand why you need to create a terminal session to run flameshot gui are you by any chance using Gnome? If so, read this part that already exists in the documentation and doesn't need to install anything new:
https://flameshot.org/docs/guide/wayland-help/#gnome-shortcut-does-not-trigger-flameshot