j@HQ:~$ gnome-screenshot
The program 'gnome-screenshot' is currently not installed. You can install it by typing:
sudo apt install gnome-screenshot
j@HQ:~$ sudo apt install gnome-screenshot
[sudo] password for j:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  liblivemedia61 libllvm5.0:i386 libpcre2-16-0 libplacebo2 libvulkan1
  linux-headers-4.13.0-25 linux-headers-4.13.0-25-generic
  linux-headers-4.13.0-30 linux-headers-4.13.0-30-generic
  linux-image-4.13.0-25-generic linux-image-4.13.0-30-generic
  linux-image-extra-4.13.0-25-generic linux-image-extra-4.13.0-30-generic
  linux-signed-image-4.13.0-25-generic linux-signed-image-4.13.0-30-generic
  python-olefile
Use 'sudo apt autoremove' to remove them.
The following NEW packages will be installed:
  gnome-screenshot
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
Need to get 52.5 kB of archives.
After this operation, 283 kB of additional disk space will be used.
Get:1 http://nl.archive.ubuntu.com/ubuntu bionic/main amd64 gnome-screenshot amd64 3.25.0-0ubuntu2 [52.5 kB]
Fetched 52.5 kB in 0s (382 kB/s)
Selecting previously unselected package gnome-screenshot.
(Reading database ... 291715 files and directories currently installed.)
Preparing to unpack .../gnome-screenshot_3.25.0-0ubuntu2_amd64.deb ...
Unpacking gnome-screenshot (3.25.0-0ubuntu2) ...
Processing triggers for gconf2 (3.2.6-4ubuntu1) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu3) ...
Processing triggers for libglib2.0-0:amd64 (2.54.1-1ubuntu1) ...
Processing triggers for bamfdaemon (0.5.3+18.04.20180207.2-0ubuntu1) ...
Rebuilding /usr/share/applications/bamf-2.index...
Setting up gnome-screenshot (3.25.0-0ubuntu2) ...
Processing triggers for man-db (2.8.1-1) ...
Processing triggers for gnome-menus (3.13.3-11ubuntu1) ...
j@HQ:~$