You'll need to do this via the command line (e.g. by SSHing into your Pi or other machine that OctoPrint is installed on - note that the password for SSHing into the Pi is not the one you use to access OctoPrint's web interface, on OctoPi it defaults to the username "pi" and password "raspberry").  OctoPrint 1.3.12+  SSH into your machine Activate the virtual environment. On OctoPi: source ~/oprint/bin/activate  Run octoprint user password <user> with <user> being the name of the user for whom y...