The most important thing when sending an invoice is that it is paid quickly and error-free. #PeppolFirst means that we automatically check every customer to confirm they have a connection to Peppol (with a Peppol ID). If so, the invoice is also sent via Peppol. Our software does everything automatically, so you don't have to worry about a thing.
Should the customer not have a Peppol ID yet, the default fallback is sending a pdf and xml invoice by e-mail with a deeplink. Another default option can of course be selected in your software.