Can I add a Canadian Apple ID to my iPhone 13?

You cannot simultaneously use two IDs on an iPhone. You would have to sign out of one ID and then sign in with the other. Note that this could raise issue with iCloud syncing services.

Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac --> https://support.apple.com/HT208242

If another Apple ID is signed in you may need to enter the password for that ID to sign out of that ID first.

Click on this link to learn how to 'Sign in with your Apple ID' --> https://support.apple.com/HT204053

Some questions have answers we do not like, sorry. If you live in Canada, you use the Canadian services.

The sections below are copied from the USA Apple Media Services Terms and Conditions document but I suspect they are very similar for all versions of this document --> https://www.apple.com/legal/internet-services/itunes/us/terms.html - Last Updated: September 20, 2021

"Our Services are available for your use in your country or territory of residence (“Home Country”). By creating an account for use of the Services in a particular country or territory you are specifying it as your Home Country."

"Terms found in this Agreement that relate to Services, Content types, features or functionality not available in your Home Country are not applicable to you unless and until they become available to you. To see the Content types available to you in your Home Country, go to the Services or visit https://support.apple.com/en-us/HT204411. Certain Services and Content available to you in your Home Country may not be available to you when traveling outside of your Home Country."

If you do not want to have to keep on signing in and out of different IDs, or changing countries on a single ID, you could consider getting a second iPhone and have one for each country with two IDs set one to each country.

If you're doing this because you need particular apps, ask the deelopers to extend their offers to other countries.

Click on this link to discover 'How to contact an app developer' - hhttps://support.apple.com/HT207959