How to tell if Unity ads are being blocked by a firewall

I myself have a firewall, so if I try to test the ads on my game using WiFi, the screen goes black and stays there. Of course, using data will show the ad for me, but I don't want the game to do that for anyone using WiFi that might have ad blocking services. I need a way to tell if the player can connect to the ad services and/or if the ads are being blocked