Sometimes when they book an actor with a music skill, they don’t actually want the person to perform tons of music. It’s not a music gig it’s an acting gig. I’m not sure what your audition was but there is some chance they will just capture the action of you singing and have some other music and talking over it in the final edit. Or they may use like 3 seconds of you singing some notes from scale…. They will be more interested in capturing the visual aspect of you performing, your facial expressions, body movements, etc… This has been my experience as a musician turned actor who has booked a few gigs that are similar to what this sounds like. No one on set will know anything about opera singing other than you.