EU OSS registration - how do I tell Amazon I have one?

I primarily sell in the UK, but do some business on Amazon Europe. I applied for VAT registration in a number of EU countries, but my German & French VAT numbers were pending for a long time, and so my Amazon.de account was deactivated earlier this year under the new German tax law.

Finally, on Thursday I received a French VAT number and OSS registration against that French VAT number. I haven’t yet received the German VAT number, but I understand all I need is OSS.

However, I don’t see where I tell Amazon about the OSS. The help page states “Germany tax obligations … Upload your German VAT identification number or provide evidence that you opted into OSS here.” - https://sellercentral.amazon.co.uk/tax/consolidatedRegistrations?ref_=macs_xxvatinf_cont_acinfohm

That page (“List all VAT/GST registration numbers you have”) doesn’t appear to have any way to mark or update a particular VAT number as OSS-enabled.

I tried to raise a seller support case, but it was auto-closed because my German account is deactivated. Attempting to open an appeal on Amazon.de redirects me immediately back to the help page - this is either a mistake or they just don’t want people asking questions.

Has anyone managed to upload an OSS number into seller central & can point me in the right direction? Alternatively, any suggestions on how I can submit an appeal when the “submit an appeal” button on Amazon.de is broken?

Cheers
Patrick

• Just to clarify, all my other Amazon EU/UK/US accounts are healthy. It’s just Amazon.de which is deactivated due to the lack of a German VAT number or OSS registration.