Non-Brave Pop Ups

This is not about Brave pop ups to earn rewards. I am getting small pop-ups on my Windows desktop in the upper right corner of page. They are grey and from different companies every time. They’re about half the size of Brave reward pop ups. They cover key info I need and I have to turn them off by clicking an X in their upper right corner. I don’t want to take the time to do this all the time. How do I turn them off?