You can watch the official music video here to see their performance and the choreography mentioned:
The dance moves in the music video were choreographed by Scott and Brian Nicholson , who are frequent backup dancers and collaborators for Ariana Grande. Troye Sivan Feat Ariana Grandedance
It was written by Sivan, Leland, Noonie Bao, and the song's producer, Oscar Holter. You can watch the official music video here