The Vend partnership is exciting, and I followed your link @hellowworld and got even more excited. But then I saw the fine print on the Vend US page: "Afterpay is only available in Australia and New Zealand."
It is the same for the Vend UK page. It shows Afterpay, but again states ".....only in available in AU & NZ".
https://www.vendhq.com/uk/afterpay
But US will definitely be soon!