Can I run Fortnite at 100 FPS on a PlayStation 5?

Currently, it is only possible to run the game at 120 or 60 FPS on a PS5.

If your monitor doesn’t support a refresh rate of 120Hz or higher, you might not be able to enable the 120 FPS mode in Fortnite.

To enable 120 FPS in Fortnite you can follow the steps in process:
How do I enable 120 FPS in Fortnite on my PlayStation 5 or Xbox Series X|S?