His beak may be very painful for a few days. So it is important to keep him drinking. Offer watery chicken feed made into a mush for him to eat. If the beak is just cracked, it may heal. Empty tea bags can be torn and used with superglue to repair some breaks. Here are a couple of good threads to read with other links: https://www.backyardchickens.com/threads/upper-beak-broken-off.1199245/