As Pryncess99 said, the SA letter, the first one which tells you which VO your application is being sent to, tells you to submit the documents for the CSQ.I have the same question. We reached Medical request stage without CSQ which will take 4-5 months to process. How come it won't affect our application
You need this letter as part of the CSQ application. You should search your e-mail for this pdf if you haven't saved it yet. You should be able to search for it in your inbox with the terms "CPCS Client Notification". You're supposed to get this e-mail before AOR2 so if you haven't received it you'll want to contact IRCC.
It should look like this and it tells you where to go to :
https://i.imgur.com/bZ32yGM.png