[2021] Launcher unable to update past 2020.5 on Ubuntu

I just deleted the launcher installation on my Ubuntu 21.04 installation. When I ran the game the launcher installed okay, and downloaded an update. After a couple of launcher restarts it had updated itself to 2021.6 and ran without error.

So I can confirm that the repo itself is fine. Why you are getting that 403 Forbidden error is a mystery!

Can you confirm that all traffic to and from api.paradox-interactive.com is allowed through all your firewalls? Also api.paradoxplaza.com  

Great!

You should now be on launcher 2021.7 which just came out.