Hi, @gabriel1085! Welcome to the Vercel Community.

I've not set-up this guide before but from what I'm seeing your post, I hope the following pointers can be helpful.

1. Your domain should be pointed to Vercel, not Shopify as Vercel will handle the routing and serve your Next.js application.
2. In your Shopify admin, you need to set up your domain as a custom domain, but it should be configured as a subdomain (e.g., shop.yourdomain.com).
3. In your Vercel project settings, you should add both your main domain (yourdomain.com) and the Shopify subdomain (shop.yourdomain.com) . 4.Your Next.js application should handle all routes, including product pages (PDP), product listing pages (PLP), and others. You'll need to implement these pages in your Next.js app and fetch data from Shopify's Storefront API .
4. For the checkout process, you'll need to redirect to Shopify. This can be done by setting up a redirect in your Next.js app for the checkout route

Let us know how that goes!