Deborah McLean provides the answer

Mornings can be tough for any family in the whirlwind of getting out of the house. Let your child know that his or her job is to go to school and then try to talk openly and honestly about why he or she doesn’t want to go. Sometimes the best time to talk to your child is before bedtime when everyone is a bit more relaxed and you may be cozy together sharing a book or another nighttime ritual. He or she may be having some difficulty with a peer or may be struggling with an assignment. Let your child know that you want more than anything for them to be happy and comfortable at school. Then it is important to follow up with your child’s teacher. Reassure your child that his or her teacher needs to know what is going on.

Coordinate a plan of action with the teacher and a check in time, maybe the following week, to see if your child’s feelings about school have improved. As principal, I also appreciate when a parent lets me know that a child is refusing to come to school. I make sure to check in with that child myself, often casually. I will also make my own observations around social touch points like recess and lunch. It is my experience that within a few days the child feels good about coming to school again.