Yes—if the heater and stones are designed for water. But that does not make the room a steam room.
A traditional sauna heats the room and a mass of sauna stones. When suitable water is thrown onto those hot stones, it vaporizes and creates a temporary rise in humidity often described by the Finnish word löyly.
Harvia describes its stone-heavy Cilindro heater as producing different qualities of steam depending on where water is thrown on the stone pillar.
A dedicated steam room relies on a steam generator and is designed around sustained very high humidity. That changes waterproofing, surfaces, drainage and construction requirements. Outdoor traditional sauna kits should not be treated as steam-room enclosures unless their manufacturer explicitly says otherwise.