Originally Posted by
docbert
Keep in mind that if you're not a US/Canadian citizen then you will need to obtain an eTA for travel to Canada. The fact your not actually planning to go to Canada isn't relevant - the airline won't let you onto the first flight without it.
Well, that fact may be relevant. If the OP isn't on a Canadi>n passport or otherwise has Canadi>n residency, the airline may not let the OP check in for the trip altogether without proof of onward travel out of Canada.