How to disable or enable Player's ShiftLock with a script(not changing StarterPlayer properties)?

So I tried to disable or enable player's shiftlock for a gun system, but I can't find the way to do it(I tried changing the camera CFrame, making the Humanoid.AutoRotate false, but it didn't work as I wanted to.) Is there a way to do it?

If StarterPlayer has a shiftlock property then surely just do

game.StarterPlayer.Shiftlock = true 

I may be a dumbass but still