openmediavault 2.1 error Package apt-transport-https is not installed

oot@openmediavault:/# dpkg -i openmediavault-omvextrasorg_latest_all.deb
Selecting previously unselected package openmediavault-omvextrasorg.
(Reading database ... 40854 files and directories currently installed.)
Unpacking openmediavault-omvextrasorg (from openmediavault-omvextrasorg_latest_all.deb) ...
dpkg: dependency problems prevent configuration of openmediavault-omvextrasorg:
openmediavault-omvextrasorg depends on apt-transport-https; however:
Package apt-transport-https is not installed.

dpkg: error processing openmediavault-omvextrasorg (--install):
dependency problems - leaving unconfigured
Processing triggers for openmediavault ...
Restarting engine daemon ...
Errors were encountered while processing:


solution :
 apt-get -f install

Then continue install plex server