@Anonymous User
Welcome to the forum. No you won't be able to watch the fight with any of the NOW TV sports passes, they only give you access to Sky Sports live channels.
Sky Box Office have confirmed they are showing the fight which means it should be available to watch on their online version, but that's only available to watch on PC/Mac, iOS/Android phones/tablets or Now TV Box.
More info on how it works here
https://help.nowtv.com/article/can-i-watch-sky-sports-box-office-events-on-now-tv
