God rays (a.k.a Sun shafts) aren’t lens flares.
[mention|8hXhwX2OPvqLiF4EhAZofw==] Unity 2017 introduced a new Post Processing Stack (more information here) that made the old ‘Image Effects’ obsolete. Sadly, there is no such effect in the Post Processing Stack (and never will be), but free third-party assets for volumetric lighting exists - such as Aura or Vapor. Give them a try 