Does it automatically insert anchors? Or what do I have to do?

I’ve installed and activated the plugin on a site with about 40 pages. I guess I don’t understand how it works. Does it automatically look at each page and insert anchors where it finds <h1>, <h2>, etc? Or do I have to do something? Manually typing in the anchors is something I can do w/o the plugin. Or is there some button hidden somewhere that I click to get it to add the anchors?

I admit, I’m an idiot. It’s probably obvious, but I’m stumped.

https://www.ads-software.com/plugins/wp-anchor-header/