I adjusted the script for EndNote 20 and did a little error checking along with user interaction. Hope this helps.
The script is in the zip file - just extract it and run. This script is an exe file - so windows only. It is triggered by holding down the Windows key and the b key (win+b). If you are interested in the AutoHotKey source code, let me know and I can send that as well.
UPDATE: 20210421 - I just updated the script to work better on more systems.
EndNote20 Backup.zip (398 KB)
EndNote 20 Backup.zip (398 KB)