@Cenk PM does not offer service outside of the US and Canada. If you travel a lot, you might want to consider going to a carrier that does - but trying to change Canadian cell plans while outside of the country is going to be difficult (e.g. to port your number you would need to reply to a text from your PM account, but that won't work because you don't have service). It might be something to consider when you return to Canada.
Instead, as others have mentioned, your option is to buy a local SIM or eSIM from a Mexican provider. Depending on what you buy, that may get you just data or it may get you calling and texting as well - albeit on a Mexican number. And of course, you can always use a voice over data service like WhatApp or FaceTime to make calls - but that really only works if the people/organizations you need to call also use the same service.
There really isn't going to be any way to get calling/texting on your PM phone number, unfortunately.
