What do you mean that you lost it?
After getting Pr only 1 years, I went back then live in my home country up to now ( over 5 years ), so the pr was lost .
Your PR does not "automatically lost".
You likely do not have a valid PR card (expired one) and you do not meet your RO.
BUT if you have US visa/or can enter via US land border into Canada, you can still travel to Canada with your COPR.
Or apply for PRTD and see if you get it or not to travel direclty via air if it's approved.
You cannot apply for TRV until your PR is offically revoked or you apply to renounce it and that has been processed.