Norton app for Safari is not compatible with your version of macOS or Safari browser

To install the new Norton Apps for Safari, your Mac must meet the following system requirements:

• Mac OS X 10.14.4 or later

• Mac OS X 10.13.6 with Safari 13.x

If you have an older version of Mac OS or Safari, we recommend that you update it to the supported version. For more information, read the Apple support article: How to update the software on your Mac