Product details page is a 404

Hi! I did a lot of stuff but it’s impossible to fix for me, so hopefully you can help so i can finnaly start a really small webshop; 5 hours of finding out now.

Anyway; i synced some test’ product and it’s showing op in the ‘products’ page but when i click on ‘show product’ i get a 404.

In the Shopify WP plugin i see the products, but i can’t make the ‘detail page’ working within my wordpress page.

My settings:

– detailpages on ‘general’ are one
– product links to wordpress
– i synced the product and they are visible in the admin side.

Would be very awesome to fix this!

The page I need help with: [log in to see the link]