This product has only been sold by Amazon and the brand’s website in the UK and was never distributed to UK resellers, only in the US.
There could be one or more reasons why no-one is selling it in the UK and parallel imports issues may not be the only ones.
Is it legal in the UK? Labelling acceptable? Maybe there is a UK version which only the brand stocks. etc etc
Chances are that the brand won’t allow it but check for other reasons too.
Buying items from a US distributor to sell on the UK marketplace can potentially violate Amazon’s Parallel Import Policy if you don’t have the trademark owner’s permission to sell their products in the UK.
To stay compliant, confirm with the brand or trademark owner whether they allow their products to be sold in the UK and obtain their explicit authorization if needed.
You’ll get a parallel import complaint.
I have seen them on eBay and the brand has a website in the UK where they sell them. The packaging of my product looks like the one supplied by the UK site.