After a Signet integration has been enabled for your company super admin users can add in cosigners where these individuals will be selected as cosigners from a list before a contract is sent out to the new employee.

Go to your Profile - Integrations/Apps - Integrations - Signet

Here you can add new cosigners by putting in full name, ssn and email. You can also edit or delete existing cosigners by clicking on the three dots to the right to the cosigners name.