It doesn't appear as if Robbie Amell actually has a role in the film as he posts on his Instagram that he "asked 1000 xmen questions," which sounds like something a "fan" would do.
In addition, Amell is currently in Montreal to film Nine Lives, which stars Jennifer Garner, Kevin Spacey and Christopher Walken. X-Men: Apocalypse is filming in Montreal as well.
You never know, though, perhaps Robbie Amell is killing two birds with one stone.
"X-Men: Apocalypse" has a May 27, 2016 release directed by Bryan Singer starring Jennifer Lawrence, Michael Fassbender, James McAvoy, Nicholas Hoult, Evan Peters, Channing Tatum, Hugh Jackman, Ian McKellen, Rose Byrne, Sophie Turner, Tye Sheridan, Alexandra Shipp and Oscar Issac.