Irish documents for German VAT registration

I am registering for VAT in Germany and Amazon wants me to upload a “Certificate confirming your business activities”. I am a sole trader based in Ireland. So far I have uploaded a CRO certificate and a Certs of Residence but they have both been rejected.
I am finding it impossible to get the actual name of the document from Amazon so I don’t know what to send them. Do you know what document I need to give them?