@Override
        public String getName() { return "duo-redirect-uri"; }
The property within guacamole.properties which defines the redirect URI
that Duo will call after the second factor has been completed. This
should be the URI used to access Guacamole.
extensions/guacamole-auth-duo/src/main/java/org/apache/guacamole/auth/duo/conf/ConfigurationService.java