I am trying to enable inventory tracking in zoho books.  I have watched every video I can find including ones put out by zoho and they all say the same thing...Settings -> Preferences -> Items and click the check box to enable.  however when I got to settings->Preferences->Items there is no box to check.  I have searched everywhere and I do not see any options to enable inventory tracking.  I am very new, like I just opened a zoho books account today.  Please tell me what I am missing