Quick question: How to get icons back

I sort of messed up and then fixed my configuration.yaml but I think I’m now missing some of the icons (like the play button) down the left side. How do I get those back?

Long press the column title “Home Assistant”

Interesting. I see how I could delete icons when I do that but how do I add things to the bar?

Press the “+” symbol next to the items that have been deleted.