How Would You Use The SetRoll() Camera Function On The Custom Camera Mode?

How would you be able to make the player's CameraType be Custom and work with the SetRoll() function? If this is not possible, are there any alternative functions or methods to tilt the camera on the z axis?

Screen Shake Local Script:

local cam = workspace.CurrentCamera
cam.CameraType = Enum.CameraType.Scriptable ---has to be set to this to work
local char = script.Parent

while true do
	for i = 1,10 do
		cam:SetRoll(.001)
		wait(.01)
	end
	for i = 1,10 do
		cam:SetRoll(-.001)
		wait(.01)
	end
	wait()
end