Blocked Extension on High Sierra 10.13.6
I am having trouble to install anti virus, such Kasperski or Sophos. The system is telling me that the extension was blocked. I clicked "allow" under Privacy and security, but nothing happened. I was not able to load Kasperski. Sophos is telling me that the "computer is vulnerable" . I uninstalled the programs, and tried again, but now I don't see the "allow button" at all. Any ideas what to do?
iMac Pro (2017), macOS High Sierra (10.13.6)