The option to download a list of attendees is only available * to the person who set up the Teams meeting * while the meeting is still in progress
If you are the Organiser if a Teams meeting you can download a CSV file with details of people who attended the meeting.
Go to the Participants panel and click on the three dots.
Choose Download attendance list.
This will download a file named meetingAttendanceList.csv
If you are using these lists, for example to monitor attendance at weekly seminars, you will need to rename them as appropriate.
You can open the file in Excel. It shows details of who attended, when they joined, and when they left.
For more, see the Microsoft help page Download attendance reports in Teams.