I’m having the same issue. Being asked for verification in the Shopify Facebook channel but unable to proceed because I’m a sole trader and don’t have a CRN.
I’ve just had this from Meta support.
We will have to forward your case to our internal team for further investigation on the business verification since it is asking you for a CRN number even though you are located in UK. We will put this chat session on hold while the investigation is on going. Once, we have updates on the case we will be contacting you here on this same chat thread.