Dual Canadian citizens can no longer travel to or transit through Canada by air with a non-Canadian passport. You need a valid Canadian passport to board your flight.
Dual Canadian citizens need a valid Canadian passport - Canada.ca
If you do not have a valid Canadian passport, and present a foreign passport or other document during check-in once this process begins, you may experience delays or be prevented from boarding your flight to Canada.
As part of recent changes to Canada eTA program, U.S. green card holders or lawful permanent resident of the United States (U.S.), no longer need Canada eTA.
At check-in, you'll need to show airline staff proof of your valid status as a permanent resident of the U.S.
When you arrive in Canada, a border services officer will ask to see your passport and proof of your valid status as a permanent resident of the U.S. or other documents.
When you travel, make sure to bring - a valid passport from your country of nationality - proof of your status as a permanent resident of the U.S., such as a valid green card (officially known as a permanent resident card)
You are eligible to apply for a Canada eTA if satisfy the conditions listed below:
If any of the above condition is not satisfied, then you must instead apply for a Canada Visitor Visa.
Based on your answers, for the purpose of your current travel, you are not eligible for Canada eTA.
However you may be eligible for a regular visa to visit Canada. Learn more about Canada Entry Requirements by country