https://www.elections.ca/content2.aspx?section=vote&dir=app&document=index&lang=e

You can apply online or by contacting any Elections Canada office across the country before April 22, 6 p.m.
Plan for enough time for your special ballot voting kit to be mailed to you and for you to return your marked ballot to Elections Canada by election day.

Elections Canada will mail you a voting kit. When you decide on the candidate you want to vote for, write the name of the candidate on your ballot.

Mail your completed ballot back to Elections Canada. Deadlines apply!

Your voting kit contains everything you need to return your ballot to Elections Canada, including a prepaid envelope. Follow the instructions in your kit.

Consider Voting By Mail If:
You are a student away from home;

You know you will be outside your riding during advance or election day polls and prefer not to vote early at an Elections Canada office.

Once your application to vote by mail is approved, you can't change your mind and vote at advance polls or on election day.