Posted September 21, 2023

Go to the GoG website in your browser...
View the Cyberpunk 2077 Store Page there. If you're logged in, you should see "By as a Gift" and "Go to my Library." Obviously, click on "Go To My Library."
When you're in your library, point to the Cyberpunk 2077 item, then click on the down-arrow that appears. Select View Downloads from that menu.
It will take you to a page that will let you "Install Cyberpunk 2077 with GoG Galaxy." Click on the "Download and Install Now" button. It will download a file called "GOG_Galaxy_Cyberpunk_2077.exe" (Make sure your GoG Galaxy is NOT RUNNING before you click on that file. Might want to reboot, just in case.)
That file will run GoG Galaxy and you'll *FINALLY* see "Importing" and a percent-complete -- it's importing your owned games.
It will take you to the Cyberpunk 2077 page inside GoG Galaxy, where you'll *finally* see an Install button. It should automatically start the install after a moment or two. If it doesn't, the Install button, which starts off greyed-out, should become available and you can then click on it and install the game.
Best of luck.

To other struggling here is what I've done.
I've installed GOG Galaxy client, logged in and saw 0 games in the library, only my wishlist.
Then I've found a post here on forum about how to re-install the client properly, so I uninstalled the app, deleted all GOG-related folders from AppData\Local, ProgramData and Program Files (x86) folders. Then I've installed the client again (I've used the offline installer this time, but I don't think it matters) and still got 0 games in library. I've tried to download and launch "GOG_Galaxy_Cyberpunk_2077.exe" from the game page, but it still showed the game as not owned. But once I've closed the client and killed all GOG Galaxy related processes in Task Manager and then launched "GOG_Galaxy_Cyberpunk_2077.exe" installer again it finally worked! It started downloading and even imported all my other games.