Set this to Performance (Lower Graphical Fidelity) . It offloads the heavy lifting from your GPU and can often double your frame rate.
Your operating system can sometimes "strangle" your hardware. FORTNITE FPS BOOST GUIDE FOR GAMING
Search for "Game Mode" in Windows settings and turn it ON. It prioritizes the game for CPU and GPU resources. Set this to Performance (Lower Graphical Fidelity)
Set this one step above your monitor’s refresh rate (e.g., 165 FPS for a 144Hz monitor) to keep frame times consistent. FORTNITE FPS BOOST GUIDE FOR GAMING