Solving No package ‘gtk+-2.0’ found on Linux Mint
This Tip Try to Solve No package ‘gtk+-2.0’ found on GNU/Linux Mint 18.x/19.x/20.x/21.x/22.x desktop – Step by step Tutorial.
And to solve this Issue you have to Install the GTK 2 Development Library.

1. Terminal QuickStart
How to QuickStart with Command Line on Mint
First, Update the Apt Repo Sources with:
sudo apt update
2. Installing GTK 2 Dev
Then to Install GTK 2 Dev on Mint
Simply play:sudo apt install libgtk2.0-dev
Authenticate with the User Admin Pass.
If Got “User is Not in Sudoers file” then Look: Solution