When only the installer's account can push (unauthenticated connection error)
Introduction
When this error appears on a different account in the organization, when the installer's account has no problem pushing, it means the Zoho Books connection is not active.
Connect zoho books.
Go to the following:
Zoho books settings > integration and marketplace > installed extensions > view details on einvoice plugin
if this connection is anything other than green (typically yellow or grey), make sure to click on it and reconnect the plugin.