It's episode 14,actually
It can’t be season 2 episode 14 cause there are only 4 episodes in season 2 so somewhere in season 3
On Netflix it’s episode 14 of season 3 when I meet him
I believe it is first seen at the last episode of the second season, really at the end, then later see him and his real identity in the third season (on netflix, at least).
It isn’t in season 2 because there are only 4 episodes and he isn’t in any of them