Modula Right Click Protection
Modula Right Click Protection will allow users to prevent visitors from downloading images by disabling right click and Alt+click. This premium extension allow you to retain full ownership of your creative work. To deter visitors from downloading images it also disables CTRL+U so they cannot see the page's source code.
To activate this setting you will have to have this extensions installed. Please see here how to install extensions from your account.
Once installed and active, you can enable it by going to your WP dashboard > Modula > Galleries > edit your gallery > scroll down to Misc under Settings > and toggle it to 'ON'.