Accounting > Configuration > Journals > Sales Journal. Under Advanced Settings, the Electronic Data Interchange section is empty and no way of changing/adding something.

1. PEPPOL Configuration Review:

• Ensure PEPPOL is still enabled in your Odoo settings. Go to Accounting > Configuration > Journals > Select your Sales Journal. Under Advanced Settings, check if Electronic Invoicing is enabled and the Peppol BIS Billing 3.0 format is selected.

2. Customer PEPPOL Information:

• Double-check the customer's PEPPOL information in Odoo. Go to the customer form, navigate to the Accounting tab, and verify the Electronic Invoicing section. Ensure the Peppol EAS code and Endpoint are filled correctly. It's best to confirm these details directly with your customer if possible.

3. Odoo Documentation :

• Odoo provides comprehensive documentation on Electronic Invoicing (EDI), including PEPPOL: https://www.odoo.com/documentation/17.0/applications/finance/accounting/customer_invoices/electronic_invoicing.html