Do I need to backup "Duplicacy" (like the program files)

So if I have performed a backup on one computer and put all backup files on an external drive, what happens if my original computer (where Duplicacy is installed) is no longer available? In other words, if I buy a brand new computer, can I still restore all of the files that are on the external drive or did I make a mistake by not backing up the “temporary directory” “log directory” and other items related to the Duplicacy program?

If I need to back up Duplicacy as well, how do I do that?

Have a look at this thread: How do you restore backup on a new computer in web ui?

no, you don’t need to backup anything. Just keep the encryption password in the safe place