Please follow the steps below on how to send your documents with the purchased stamp:                                                                          

Once you login, the website will be redirected to the Account Dashboard.
Once inside, you will see a button called My Documents.
You will then see all of the existing documents/forms that are active on your account.
Click the icon "More" and you will be directed to the Action panel where you can see Postal Mail.
Click the icon and click "Send it for me". Fill out the form and finally click "Submit".