Adding Custom Card to HA

I’m beginning with HA, now I want to add the Custom Card option to my HA. I found the one which is used by alot of people.

But even with the installation manual, I can’t figure out how to add this to my HA. Can one of you help me with thos problem?

What I want to achieve with the add-on is that the icon color will change depending on the state of the entity (‘Online’ or ‘Fault’).

The easiest way is to install HACS (Home Assistant Community Store). That way you’ll also get automatic updates.

Edit: An add-on is not the same as a custom card or integration… Just being pedantic… :grin: