@Anonymous User Welcome to the community. You're given that option when you sign up to broadband in case you want to take the passes out at the same time. Once you're a broadband customer the discount should be applied automatically whenever you purchase a pass, so there's no need to go via a special 'offer page'. So you should be able to go ahead and buy a cinema or entertainment pass and get a £3 discount (no discount on other passes). More details here
https://help.nowtv.com/article/what-is-now-broadband
Check when you buy the pass that the discounted price is showing, if it isn't then give the broadband team a call and they can help. You can find the telephone number for the Broadband Team by going to your My Account > Broadband and Calls page
https://account.nowtv.com/my-package
and click the Moving Home section.
NOW are looking for users to join their Customer Feedback Group and help improve the service. If you're interested read more here and sign up.