https://www.canada.ca/en/immigration-refugees-citizenship/services/visit-canada/eta/eligibility.html
“Travellers who are exempt from the eTA requirement
U.S. citizens are exempt from the eTA requirement and must carry proper identification such as a valid U.S. passport.
As of April 26, 2022, lawful permanent residents of the United States are also exempt from the eTA requirement and must show these documents for all methods of travel to Canada:
- a valid passport from their country of nationality (or an equivalent acceptable travel document) and”
- a valid green card (or equivalent valid proof of status in the United States)
