I am a lawful permanent resident of the U.S. (green card holder). Do I need an eTA? No. As of April 26, 2022, lawful permanent residents of the U.S. must show the following 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) https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1053&top=16
https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1053&top=16