@Anonymous User
Welcome to the forum.
Have you tried following the steps in this help articl to apply your voucher to your account?
http://help.nowtv.com/article/Apply-Voucher-Sky-Movies-Month-Pass
If there isn't an apply a voucher option and you already have an active pass then this may be because of a slight bug causing the option to disappear when you already have a multi-month offer applied.
If this is the case, the best thing to do is to cancel the pass (you will still be able to watch up to the expiry date) and then when the expiry date has passed and there is no longer an active pass on your account, the option to apply a voucher should be back again.
