Recommend a very useful screenshot tool Flamesho in ubuntun
The installation steps are as follows:
$ sudo add-apt-repository ppa:harish2704/ppa1
$ sudo apt-get update
$ sudo apt-get install flameshot
After the installation is complete
In the system settings -keyboard-shortcuts-custom shortcuts, add a shortcut key. The
name is The flameshotcommand is /usr/bin/flameshot gui. After confirming, click this line and pressalt+x