rost@DEBIAN999:~/Downloads$ sudo dpkg -i opera-stable_73.0.3856.329_amd64.deb
[sudo] password for rost:
Selecting previously unselected package opera-stable.
(Reading database ... 135642 files and directories currently installed.)
Preparing to unpack opera-stable_73.0.3856.329_amd64.deb ...
Unpacking opera-stable (73.0.3856.329) ...
Setting up opera-stable (73.0.3856.329) ...
update-alternatives: using /usr/bin/opera to provide /usr/bin/x-www-browser (x-www-browser) in auto mode
update-alternatives: warning: skip creation of /usr/share/man/man1/x-www-browser.1.gz because associated file /usr/share/man/man1/opera.1.gz (of link group x-www-browser) doesn't exist
update-alternatives: using /usr/bin/opera to provide /usr/bin/gnome-www-browser (gnome-www-browser) in auto mode
update-alternatives: warning: skip creation of /usr/share/man/man1/gnome-www-browser.1.gz because associated file /usr/share/man/man1/opera.1.gz (of link group gnome-www-browser) doesn't exist
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) ...
Processing triggers for shared-mime-info (1.10-1) ...
rost@DEBIAN999:~/Downloads$

Работает