If you linked your application successfully, why didn't you upload/submit your Schedule A on your CIC account? You login to your CIC account and you see a request letter, then at the bottom you click on 'View Submitted Application' and it shows you what files you need to upload and where.
Submitting by IRCC Webform or by mail will take forever for them to acknowledge it. You only do that when you have a technical issue or if you can't upload to your online account for some reason. These instructions should have been in your request letter.