Ok first step is follow the instructions you get when you run the install.
You can rebuild it and they might trigger again.
Then you will look for the files you need to delete. In Linux you use the rm command, you can get more info on it by typing man rm be careful with it, it will delete whatever you tell it to delete.
If you have one of the standard DE’s like Gnome, KDE etc you don’t need a custom authentication agent.
We can worry about that later. Just start with running the build again to get your instructions, delete the file and run the diag command it suggests. It also suggest doing a reboot after the install to ensure permissions are ok.