then,
kaye@laptop:~/Downloads$ sudo dpkg -i viber.deb
Selecting previously unselected package viber.
(Reading database ... 268263 files and directories currently installed.)
Preparing to unpack viber.deb ...
Unpacking viber (12.0.0.7) ...
dpkg: dependency problems prevent configuration of viber:
viber depends on libssl1.0.0; however:
Package libssl1.0.0 is not installed.
dpkg: error processing package viber (--install):
dependency problems - leaving unconfigured
Processing triggers for desktop-file-utils (0.23-4) ...
Processing triggers for mime-support (3.62) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Errors were encountered while processing:
viber
Thank you.