First ,have you filled the new Schedule A form;
http://www.cic.gc.ca/english/pdf/kits/forms/eIMM5669E.pdf
Secondly, anyone can upload through IRCC web form or one who has linked the application will get the message in ecas and will have an option to upload the document from GC key. If there is not option under GC key to upload documents, than send it through IRCC web form and anyone can do that.
Ok thanks I have the new forms filled out already.