The X-Men must battle a threat called En Sabah Nur, who wants to destroy the world.
Currently you can stream X-Men: Apocalypse with Disney+. If you have an existing Disney+ subscription you won't need to pay anything extra to stream X-Men: Apocalypse. It is unlikely that we will see X-Men: Apocalypse on Netflix or Prime Video in the future as Disney owns all Marvel movies and have removed their movies from other streaming platforms.
If you don't have access to Disney+ then you can still buy or rent X-Men: Apocalypse to watch online from a variety of different platforms, including Google Play Movies, Redbox, Apple iTunes and VUDU. You can rent the movie for as little as $2.99 so check it out!