You do not need to submit any proof that you have been to Canada at all, unless they send you a residency questionnaire.
If you are a Permanent Resident, you passport sometimes gets stamped and sometimes doesn't when entering the country. It depends, among other things, on the fact if you did or did not use the automated kiosk, the mood of the CBSA officer and arguably the current moon phase

Jokes aside: No matter if your passport got stamped or not, they did in fact scan your PR card or your Passport. So your border crossings are stored in the CBSA database which IRCC will access during your application.