Everyone has to have an Online Account on CIC website in order to link his/her application to that account. Through this account, one might receive messages to send/upload the required documents such as Medical, PCC ( Police Certificate ) or Schedule A form. For example I received my Medical request from my Online Account. You can see the status of your application as well. On the other hand, there is an eCAS ( electronic Client Application Status ) through which you see the status of your application somehow in more details. For example when they have received your application or when they have started processing you application or even your medical results have been received, ... etc. IRCC Web Form is platform where you can communicate with CIC. I have been asked to send my Schedule A form for example via my Online Account but since I have difficulties to upload there ( technical issues with my Online Account ), the agent asked me to send my forms via IRCC Web Form.
So you have to wait for CIC to send you a request. You may be able to upload your documents via your Online Account or just like me and a lot of people submit your forms on IRCC Web Form.