How to send invoices to 2 emails?

How to send invoices to 2 emails?

Hi! We are sending invoices to the "Customer email" field that is defined Zoho Books and is obtained/synced from a custom email field in Zoho CRM.

But in some clientes, the invoices have to be sent to 2 emails and we are wondering how this could be accomplished. We are already syncing a "email2" custom email field from CRM to Books, but I don' know how to automate that every invoice sent to that customer sets that additional email to add to "CC"

Thanks in advance!