After I updated to Mojave, I can no longer use the automator service I\'ve previously been using with the alert below.
I had this error in Terminal.app on Catalina with the simple test script of osascript -e 'tell application "Finder" to display notification "some stuff".
I was not getting the pop-up and did not find any helpful options in Settings -> Security & Privacy -> Privacy -> Automation -> Privacy (neither Automation, nor Full Disk Access). I also did not have any luck with tccutil reset AppleEvents; tccutil reset SystemPolicyAllFiles (other than unfortunately losing all my relevant preferences).
For me, the issue was that I was running the command in tmux. Once I detached from tmux, running the same command in Terminal prompted me for the relevant permissions dialog. Once allowed and reattached to my tmux session, I still could not run the command in tmux (but ran in Terminal outside of tmux). At this point I killed my tmux session, launched a new session, and thereafter was able to run this command in tmux in Terminal.