By default, Macs have a built-in feature that blocks pop-up windows to prevent unwanted interruptions and potential security threats. This feature is part of the Safari browser's security settings. When a pop-up window is blocked, you'll see a notification message indicating that the pop-up window has been blocked.
If the window won't let you click anything or won't close, the best way to close it is to force the application to quit. pop up window blocked mac