How can I restrict transport types

In the Billit API, you can send your invoices using the commands/send API endpoint. This endpoint allows you to specify a transport type.

When using Peppol as the transport type, if the customer is not registered on the Peppol network, the system will attempt to send an email to the customer. This might not be the desired behavior. To address this, you can use the StrictTransportType header.

By setting the StrictTransportType header to true, the system will prevent sending the invoice via email and will instead throw a validation error if the customer is not registered on the Peppol network. This ensures that invoices are only sent through the specified transport type.