how to make a gun stay in the same position when you turn the fps controller up

i have an fps cantroller with a gun model attached, whenever i look up the gun moves away from the camera and when i look forwards again it goes normal. the same thing happens if i look down. does anyone know how to fix this?

I guess that for that you must have the gun accompany the movement of the camera. Try to attach the weapon to the Camera. Might Work…

Just make the gun a child of the camera.