If you want in one command and not use Software source ticking then in terminal put:
sudo add-apt-repository universe
On older versions of Ubuntu, you might have to use a full source line:
sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc) universe"
To enable all Ubuntu software (main universe restricted multiverse) repositories use
sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc) main universe restricted multiverse"
Then update the package list:
sudo apt-get update
This should do!
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Thanks.