I'm trying to log in on Garmin Express Mac, but I just receive the error msg:"A Keychain error occurred."

I had the same error just today, Nov 23 2021. I honestly don't know what fixed it but I'll list all the things I did:

• Quit Garmin Express from the black triangle at the top of the screen, confirming that I wanted Garmin Express to stop running in the background.
• Turn off all pop-up/tracking in Safari (yes, really, Safari, even if you're not currently using it. So weird) by going to Preferences (Safari->Preferences) and
  • In "Privacy": Select "Always allow" for cookies and website data, and also deleting all saved data for Garmin.com in the website data that was already saved.
  • In "Websites": if Garmin.com is listed under Content Blockers, select it and click "Remove." If it is listed under "Pop-Up Windows," select "Allow."
• Quit Safari.
• In Finder:
  • Select your mounted Garmin device (showed as GARMIN on my screen), open the Garmin folder, put GarminDevice.xml in the Trash and empty the Trash.
  • Eject the device.
• Open Keychain Access in the Utilities folder inside the main Applications folder, select All Items under Category, search for 'garmin' in the search box, and delete anything that comes up by selecting that line and right-clicking, and selecting "Delete (whatever it is)."
• Reboot your Mac.

I hope that the actual answer is much simpler than this, but I am not interested in debugging Garmin's app--that is their responsibility. And they should do it.

My info:
MacBook Air running MacOS X Sierra 10.12.6
Safari 12.1.2
Garmin Express downloaded today v. 7.10.0.0
Garmin Fenix 6S