Dear @grb, thank you for replying.
When I go to a webpage for which I have imported the username&password from Google to Bitwarden,there is no any overlay containing a number.
If I press the keyboard shortcut keys,the auto-fill feature doesn’t work.
When I created the Bitwarden forum account today,the Bitwarden extension stored the username&password and when I access the site there is an overlay containing number 1.
And the auto-fill feature works.
Edit: I’ve also noticed that there are many,many duplicates of same accounts.