In the majority of divorce cases, you cannot move to another state with your child without a written agreement from the other parent. You will usually need the permission of the other parent or the court, depending on your custody arrangement.
If the other parent refuses to consent to the move, you will need to file a motion with the Court to get permission to move to another state with your child. The Court will then apply the statutory relocation best interest factors to determine whether or not the move is in the child’s best interests. For more on interstate child custody, see here.