Thanks for your replies.
So when I log in via this website to buy an extension: https://woo.com/products/shipment-tracking/?quid=5ce395250d869cb43a7d8180cb0387e9 it takes me to our WordPress page but it is an old website (somehow using the same email?) when I log out and log back in to our new website, I am unable to buy the purchase linked above?
Thanks so much for your help