Your method is named “update” rather than “Update”. So, it never fires.
You should prove this to yourself by adding a Debug.Log statement (e.g., Debug.Log(“Updating!”) as the first line of the method. You would expect to see that message filling up your Console at something like sixty times per second. But instead, you never see it at all… thus providing a big clue that you haven’t typed the magic method name correctly.