sudo nano /etc/default/duplicati
# Defaults for duplicati initscript
# sourced by /etc/init.d/duplicati
# installed at /etc/default/duplicati by the maintainer scripts
#
# This is a POSIX shell fragment
#
# Additional options that are passed to the Daemon.
DAEMON_OPTS="--webservice-interface=any --webservice-port=8200 --portable-mode"