Creating Classes inside Teams

I've been trying to create a class using Teams but what I've gotten this far is to create a team only, in which I can't assign any homework. Every time I try to assign any homework a message saying that I have to create a class pops up on the screen, even though I follow the procedures given I'm not able to find the CREATE A CLASS option (that one which its icon is a backpack). There isn't this option for me or at least I wasn't able to find it. How can I create a class so I can assign my students homework and other features related to schools?