This probably is the issue, when you download a script or binary from the internet it doesn’t have execution permission, you would have to right click on folder to open in terminal (that way don’t have to cd to it), and check permissions with ls -la
if it doesn’t have permission, change it with chmod
Having the ability to shut down the main instance of an app and run a secondary instance from backups without much hassle is the best feeling ever, I recently updated from Nextcloud v26 to v31, and having the ability to just go back to a working version if anything was wrong saved me from so much stress.