A child with laryngospasm can be a scary thing to manage. There’s no way to predict whether a child is going to get it.
You can try the usual maneuvers including a jaw-thrust, positive pressure ventilation to try to open the vocal cords, and suctioning. If these don’t work, you might consider giving the patient a paralytic, such as succinylcholine, and performing an endotracheal intubation for worsening hypoxia. Before that, what non-invasive maneuver can you try first?