When was your app received? I believe you need to go to an RCMP detachment and request your fingerprints to be taken. Here are some helpful links I found on the canada websiteJust received a request for finger print based police clearance. The letter says:
This letter refers to your application for permanent residence under the Spouse or Common-law Partner in Canada class.
In order to continue processing your application, further information is required. You must provide an RCMP police clearance certificate based on fingerprints.
Followed by details on how to do it. Anyone else received this?
https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=857&top=4
https://www.rcmp-grc.gc.ca/en/steps-getting-a-certified-criminal-record-check