customer list VAT exemption

I am a self-employed person in secondary occupation under the VAT exemption scheme.

I have one customer, also under the VAT exemption scheme, who receives an invoice; all other customers are private persons.

When I generate my customer list via Dexxter, it is empty, even though I invoiced that one customer for more than €250 last year.

Do I still need to submit a customer list and add that customer manually?