Where To Inform Of UTR?

Hi guys,

I was an idiot and went through months of stress to get verified as an individual, non business entity seller on Amazon.

Now I have registered myself as a Sole Trader via Gov.uk and have now obtained my UTR number and have my business bank account set up.

Now I want to change from an individual person to a Sole Trader Business Seller on Amazon.

I cannot find where I do this on the Account Info interface. Where do I provide my UTR number?

Thanks in advance