Review your installed apps and software, and uninstall any suspicious or unknown entries. This may include:
Restart your device in safe mode to prevent the virus from loading. Safe mode will also help you to: how to remove pop up virus
How to Remove a Pop-Up Virus: A Complete Guide to Reclaiming Your Device Review your installed apps and software, and uninstall
If pop-ups persist, your browser’s homepage or search engine may have been hijacked. Resetting your browser to its default state is often the most effective "nuclear" option. Review your installed apps and software
Check your Library/LaunchAgents folder for any remaining script files associated with the app. Step 3: Clean Your Browser Extensions