eTA TRAVEL VISA
Depending on your residency and country of origin, passengers to Canada may require an eTA Travel Visa to enter the country.
Read all about it at the link below.
Please note that you should not pay more than $7 to obtain one (be careful of sites charging up to ten times this price to assist you in the process), and it must be arranged in advance of flying.
Official Canadian Government eTA Site
(if the document isn't underlined, then it is not yet available)