Error “Not authorised to send Apple events to Terminal.” when starting Maxima
I ran into the same issue, tried the things in the link.  Eventually this is what worked for me:

Open Terminal.app
Navigate to the `Maxima.app/contents/MacOS/ folder:
% cd /Applications/Maxima.app/Contents/MacOS


Run the applet binary:
% ./applet


This finally triggered the pop-up requesting access.  Click to allow access.