Can't get Chrome remote desktop working on Linux

I need to be able to connect to computer running Lubuntu 20.04 with Chrome remote desktop. I have installed it with dpkg -i. After adding a couple of required dependencies it has set up smoothly. Then I launched it only to get this screen: Should I click the blue button it initiates downloading and installing... exactly the same deb-file (this time with GUI tools: Qapt or Discover). Round and round in circles I go...

I found this advice: How can I "Turn On" Chrome remote desktop in Ubuntu 20.04?. No dice for me. Did not change a thing.

Also, I tried to uninstall it with dpkg --purge. and install again. It is still the same.

Edit:

What I found out so far.

I found an informative answer on how to start investigating the issue in the thread Can't Configure Chrome Remote Desktop (it is not the accepted answer, but the second one).

I executed service chrome-remote-desktop status and realised the CRD service was masked, i. e. not running. Executing sudo systemctl unmask chrome-remote-desktop.service changed nothing. So, I followed the second answer (again, not the accepted one) of https://unix.stackexchange.com/questions/308904/systemd-how-to-unmask-a-service-whose-unit-file-is-empty.

It helped me to actually start the service. Now it is up and running.

Unfortunately, it has been just a part of the problem, CRD still fails to run. And finally, I have stumbled at the step usermod -a -G chrome-remote-desktop "$USER" of the mentioned thread Can't Configure Chrome Remote Desktop for it returns usermod: group 'chrome-remote-desktop' does not exist and I do not understand whether it is important (but it looks like logging does not work without this step).

For me, Chrome Remote Desktop recently updated and I was unable to start a xsession due to errors. I patched it to make it connect to the existing physical screen, which worked previously (before the update), but it doesn't work now due to (what appears to be) xauthority issues. I'm running a server, so I can't open x to all local users, so I tried for an hour to find a fix to no avail. Then, I gave up on ChromeRDP because it appears there is no solution to the problem (at least none I could devise). Anyway, I had countless issues with ChromeRDP prior to it breaking completely, including random disconnects, broken x sessions, freezing up the x session, black unusable desktop, randomly stopping working, the computer suddenly disappearing from the list of connectable computers, etc. So, the solution is to just port forward. If you can't port forward (e.x. it's a laptop), then (as far as I can tell) you're SOL. To date, I have yet to find any other suitable no-port-forwarding alternative RDP software.

I wish I could be more help and I realize that this is not much of an answer, but I hope that explaining my struggles and how ChromeRDP finally broke completely (every successive update to date has made ChromeRDP more and more buggy on Linux) might help. Unfortunately, you missed the easiest RDP software that ever existed by about 6 years. Back in 2015, ChromeRDP was as simple as one-click install on Linux and it never gave me a single issue.