How to add students to School Day in Microsoft Teams
1) Login and select your class
2) Click Students-menu
3) Expand Groups-section and select the Teams-class whose students you want to add. Make sure all the students you want to add has the checkbox checked
4) Confirm student add
5) After confirm students are being added to School Day class
6) Click the Refresh-button. The students you added will appear under Students
7) If you want to add more students from Teams group, you can always start again from phase 3.