i’m sorry you’re having issues with logging in to your game.
Lets try few Troubleshooting steps mentioned below to see if your able to resolve it.
Make sure you are not using a VPN.
Sign into Amazon Sign-In
Unlink your Amazon account from blue Steam text on the right.
Re-link the account.
Run a file check: Steam Support :: Verify Integrity of Game Files
After all steps above:
*** Shut down the computer completely. Turn it on, then run the Steam client as administratorand try the game again.**
**Please let me know by tagging my name here if that fix the issue.
Its important to follow the troubleshoot steps on this post in order to get the issue fixed. We noticed it works for most of the players that followed the steps.
If you still have the issue after this troubleshoot, please create a web ticket by going to Contact Us | Amazon Games
i hope this helps!