When you sign in to your CIC account, on the ‘view applications you submitted’ page if you scroll down it says ‘link your application to your account’ if you click on that it will take you to another page where under category you should select ‘PR Card’ and under application details you select ‘UCI and family name’. Just make sure you enter family name and place of birth exactly as it shows in your passport(upper case, lower case, any dots or any spaces), once that is done it will find your PR card application just link it to your account
Hope this helps, Good Luck