You'll always be given an opportunity to defend yourself against a proposal to deny. Sometimes, proof of alcohol or drug treatment may assist the Parole Board in making a positive decision on your file, if your conviction(s) were related to or caused due by addiction. Obtain proof of completion of programs that aided in your rehabilitation as soon as you are able. If you apply for a Record Suspension several years after attending rehabilitation programs, sometimes records proving attendance are no longer available. You may even need to go so far as to provide an alcohol and drug test with negative results to the Parole Board of Canada.
Source: https://www.canada.ca/en/parole-board/services/record-suspensions.html
