If you have lived in Canada for over 6 months since turning 18, you will be asked to provide this at some point. IRCC will give you 1 month to provide this document.
You will have to go to your local RCMP detachment and ask for a criminal record check for immigration purpose. They will fingerprint you and give you a copy/acknowledgement of submission for verification. The report will come from Ottawa directly to your mailing address within 10 days if your profile search is negative, indefinite period of time is required if you have a history with them.