Since I use Safari for QB, she clicked Settings, then Safari and then clicked on the ad blocker. If you Google " how to turn off pop up ads on iPad" you should be able to find a site that will walk you through with pictures.
If it is ads for Apple apps, you might have clicked on the push notification button when you added some apps? I always say no when they ask to push notification. Wish I could tell you more but I am not very computer literate.