what postal service does chegg use?

I’m trying to rent a textbook from Chegg but I think they use UPS. I go to Sam Houston State where apparently we have a P.O. Box for usps mail but HAVE to physically be in our dorms to receive UPS or FEDEX (kinda inconvenient and the staff can’t receive it for us). Does anyone know if Chegg actually uses UPS?
edit: I don’t know why it says its a TAMU post. Sorry, I don’t know how to change it