You have to apply as you have to prove that you qualify for the Citizenship (you present your family tree with proofs of births and marriages and whatever is needed to reach that “canadian ancestor”), once it is done, you get a “Proof of Citizenship”, that is what will then allow you to apply for Passport, Driving License, jobs… It kinda becomes your “birth certificate”. Now, to note, I got this in 2014 due to my mother being born Canadian (and me not) and it took me over a year to get my paperwork (close to two) and there is not a “temporary citizen” status, so you have yo wait until you get it to come to Canada (barring visiting of course). With the influx of submissions that this change will create you can expect those times to increase (unless they open a specific channel for it 🤞).