How Can I Do This?

Hello everyone!

I was looking at one of my competitors' blogs, and I came across a feature that caught my attention. (See the screenshot below, please.)

Does anybody know how I can do this? Is it with a plugin or is it something else?

It's a sticky bar at the bottom of the screen that I think can positively impact the conversion rate.

What do you guys think?

It's called Anchor Ad.

Ezoic does this for example.

I'm sure if you search for that, plugins will pop.