The "Primary Contact/Signatory" is the person who receives and signs the form.
Adding e-signatory (person who receives the e-signature request), should be updated via the Primary Signatory's "Settings" > "Contact Details".
From the below example, Doe Pty Ltd's e-signatory is coming from the "Individual's PRIMARY CONTACT/SIGNATORY" which is Cherry@gmail.com
The email address of the e-signature is taken from Primary Contact/Signatory, not from the Primary Email of the company.
There is an instance that your client has a different email address for their Personal tax form and for Business Form, if that is the case, you (as agent) need to add a "New Client" in LodgeiT for email address purposes only, and link it through the Business form.
Below example shows that Doe Pty Ltd's email address signatory is "Cherry@gmail.com", not the email address from "Doe Pty Ltd".