UK seller tax information for Amazon USA

I am a new seller on Amazon and it is asking for my tax information for the INFORM consumers act. I interpreted this as needing to send a letter showing my Unique Tax Reference from HMRC but Amazon won't accept this. Are there any other UK sellers that may be able to help me know what I need to submit? I have asked and spoken to different people in Amazon but I just keep getting sent the same link to guidance that says its a letter showing UTR so I am none the wiser and its saying my account will be deactivated in another few days if I can't provide what is needed.