Nvidia has developed a version of its GeForce cloud gaming service that runs in the mobile web browser Safari.
Apple will not get a cut of virtual items sold within the battle royale fighting title when played this way.
Apple is embroiled in a legal fight with Fortnite's developer Epic, which led the iPhone-maker to remove the game from its iOS App Store.
Epic has claimed that the 30% commission Apple charges on in-app gaming purchases is anti-competitive.
But Apple has accused Epic of wanting a "free ride".