Students of one class sending request to join in another class

[rahmanpragati]

We have different classes in our School. Recently I observed that the class-III we are getting requests from students of 2nd class for joining the team. I don't under stand how a student of one class can send request to join in another class. 

What do I need to do to avoid this?

[#2]

@rahmanpragati you have posted your message in the community for training and certification.  This topic would be better posted in Microsoft Teams for Education - Microsoft Tech Community