Thanks for the hint. I get to know how to link my PR card application to my GC account (for others, if you don't have GC account, I recommend you create one), it's so easy and just few steps>
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/account/link-paper-online.html
Note: In GC portal, PR Card application is different from PR (Express Entry) application. The PR Card application is automatically submitted (at least in my case) after I got my eCOPR, in the same day.
I don't have access to the PR application (since it was submitted through a representative), but now I have access to the PR Card application through the GC portal. That said, now I have access to both GC and PR portal for my PR card application.