https://www.cnet.com/news/why-fortnite-battles-nintendo-switch-ps4-arent-happening/

Nintendo Switch players can get Fortnite right now, but they won't be able to play the game with friends on the PS4.

Nintendo announced at E3 2018 on Tuesday that Fortnite is immediately available for its portable console. The game became available almost as soon as the announcement was over, opening the free-to-play game to all via the Nintendo eShop. (You can watch the full Nintendo E3 event here.)