The indirect object in this sentence is: "hockey players".
The indirect object presents to whom or for whom the action presented by the verb is done. In this case the verb is "to give". The "coaches" give the facemasks to the "hockey players". Thus, "hockey players" is the indirect object. The position of the indirect object is between the verb and the direct object. For an indirect object to appear there must always be a direct object. The direct object of this sentence is "facemasks".