This trophy previously required you to get a win in Trials of the Nine, to then visit The Spire and speak to the Emissary. Since then, Trials had been removed and you could not obtain this trophy. The requirement for this trophy now is to speak to Xur.
Xur is an NPC Merchant who appears every weekend. Friday through to Tuesday. He will appear in various locations in the solar system, be it at the tower, or on titan, or even on earth. Multiple websites online update his random spawning location, so just look it up, then go visit him. If this trophy does not pop, just log out, log back in, and speak to Xur again. Destiny is finnicky.