If you double-click on the clipboard with the checkmark icon in Meet, you have some additional icons that appear. Here is a description of the icons from the developer of the extension:
Right Click the attendance icon
The first icon will add a new sheet to the existing spreadsheet.
The Sheet will be labeled with the date and time.
Attendance will not be taken in it unless the people is reopened or the switch is flipped off and on
The second icon creates a new spreadsheet.
The Spreadsheet will have the date and time in the name.
Attendance will not be taken in it unless the people is reopened or the switch is flipped off and on
The Switch will turn off attendance taking.
The switch is synced to the Chrome profile so remember to check that it's on if it's not taking attendance.
The Feedback icon will open a spreadsheet for feedback to me. (It's a bit overwhelming but I'll be reading through them)
The Broken link icon will reset the extension (may be deprecated soon as we see how it all works)