Messages for web app on computer

I went to that page yesterday and scanned the bar code and it is working on my phone. But I can’t see messages on my computer. I go to the page below and get the bar code again. I see no way to log in.

When you have unread messages, the Messages icon in your browser tab will show a red notification and the number of unread messages.

I don’t see that browser tab. Thought maybe it was a Chrome extension but searching gives no results.

https://messages.google.com/web/authentication

Scanned again, took me to the page, now saved as bookmark

Unless I get some explanation for what this thread is supposed to be, it’s closed.