Steps in Snap: Admin > Reports > Activity completion
Steps in other themes: Course administration > Reports > Activity completion
The report displays the name of participants and the activities in which Completion tracking has been enabled. Point your cursor over the green checkmarks to see the date of completion.
Activity completion is enabled by default in new installations. If you do not see this report, you may need to turn it on for your course and each activity you want to track. To learn more, see Activity Completion Tracking.
More on activity completion tracking on the Moodle website (may be available in English only)