Shortly after you have your application approved, you will be asked to mail your passport (and your family members) to a Visa Application Center (VAC). They will then stamp it with your visa, and mail it back to you.
This stamp is not yet your Permanent Resident card. It is "only" a visa that allows you to travel to Canada only once, to do your landing.
VAC's are entities that work with Canada government to handle some process like biometrics and passport stamping. You will receive a Passport Request Letter with instructions on where and how to send your passport to them.
You might also be able to take your passport (and other required documents) in person, depending on your assigned VAC - Get in touch with them to know the right process to do so.
Note: If you will mail your passport, make sure you use a safe carrier, with a tracking system.
Note: Most of VACs around the world are temporarily closed due to COVID-19. Visit this IRCC page for more information.
To find out more about Visa Application Centers, visit this IRCC page.