I should actually ask about the inverse situation (mine) because I haven't been able to test it out yet.
I have NEXUS and I'm a US permanent resident and I have my eTA. Next month I'm flying to Montreal and I'm wondering which document I have to use on NEXUS machines. Has anyone in my situation been through this recently?
EDIT: This site seems to suggest that I'd have to use the actual NEXUS card in the kiosk in Canada, unlike entering the US where I have to use my green card.
https://www.cbsa-asfc.gc.ca/prog/nex...n-eng.html#can