read this link for obtaining police cert from the US:
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/medical-police/police-certificates/how/united-states.html
You can choose the third party option (option 2 on the link) and it's much, much faster, especially if you choose a place where they can scan your fingerprints right there (then you can skip going to a police station to get your fingerprints). We used Fieldprint and did it at a UPS store that did background checks with Fieldprint and we got the results in literally 10 minutes via an email link. Not all cities might have this, so check the link under that option and you'll have to search around to find a third-party channeler near you.
For anyone else who can't get theirs a fast way, for example if your country doesn't have a quick option, then as long as you provide a copy of a receipt that states that you've paid to obtain a police certificate within the required timeline, then you'll be okay.