Continual pop ups when in safari or chrome. I’ve run Norton scan but still continues

Don't run Norton, it is not necessary for your Mac and it only slows your Mac down. Run the free version of malwarebytyes instead

But it could be that this is not malware, but just an browser extension

Try and see, in safari if there are unexpected extensions and if they are there, delete them to see if the issue is persisting

Choose Safari > Settings (or Preferences), then click Extensions.

• To turn off an extension, deselect its checkbox.
• To uninstall an extension, select the extension and click the Uninstall button. If you can't determine what an extension does, or you don't expect to use it again, you should uninstall it.

For Chrome, follow these steps to remove any unwanted extensions

1. On your computer, open Chrome.
2. At the top right, click More   Extensions.
3. On to the extension you want to remove, click Remove.
4. Confirm by clicking Remove.