Icons on Tiles

I am just starting out with Hubitat and I'm watching some YouTube videos. I am trying to figure out how to add an icon to the tiles but the checkbox is not showing up for me. What am I missing?

Welcome to the community! What template are you using for your tile? Not all have custom icons available or icons at all. You can, however, customize pretty much anything using CSS. There is a great thread for it here:

There are also some great threads with info for dashboards here:

I thought there was another one as well but I cannot find it.

I was using the Dashboard Link which I'm also having issues with as well because it's giving me an error about it only working with the legacy dashboard.

Dashboard links have no default icon but you could add one. What release are you on? Have a look at this thread.