All Borrowers added to the deal will automatically show up in the “e-sign portal”. However, the borrower does not have to be invited to the deal (they do not need to have registered for an account). You must however, have an email for them entered in the "Borrowers" section of the application in order for them to receive the request to e-sign documents. They won't be able to make changes to the application or submit documents.
Please note: E-signing documents must be signed by each borrower, they can not be signed by one person.