Although it isn’t mandatory, you could choose to add a note in your FAQ/Help section, informing visitors about the new ads they see. This notification could also work as an introduction to In-Footer ads and inform users about ways in which they can interact with them.
For instance, you could add the following paragraph to your FAQ/Help section –
The ads appearing on the base of the browser are In-Footer ads by Affinity. Affinity’s system scans the content on a webpage and places relevant brand messages on the base of the webpage. As the mouse is hovered over the base of the browser, an ad will appear. You could choose to click on the link provided in the ad to visit the advertiser’s website.