Run capture of full screen (no us of GUI) on MacOS - How to ?

[vojtechhuser]

The macOS built in screenshot app can take screenshot with no GUI.
Press shortcut and clip is taken.
I guess that is like running the full command (and not GUI).

Can you provide newbie instructions how to configure to run a command like below on shortcut Cmd+Shift+8 ?
flameshot full --clipboard --path ~/myStuff/captures

I failed to even add flameshot to my path or run it once by specifying the path to it.
I installed via homebrew. (which will be deprecated, not sure why?)
I try to run in zsh the command and I get.

cd /Applications
pwd
/Applications
cd flameshot.app
cd Contents/MacOS/flameshot
cd: not a directory: Contents/MacOS/flameshot
cd Contents/MacOS/
pwd
/Applications/flameshot.app/Contents/MacOS
ls
flameshot
flameshot
zsh: command not found: flameshot