To see the contributions profile for the first account signed into your browser, you would use:

https://www.google.com/maps/contrib/YOUR_UNIQUE_ID?authuser=0

You cannot guess the unique ID. You must obtain it by navigating properly through Google Maps.

Why would authuser=0 appear in your search? Likely because you copied a URL from your browser’s address bar while signed into multiple accounts, or you saw it in Google’s redirect chain.

The correct way to access your contributions profile is not via the malformed keyword above. Here are the legitimate methods: