wpgraft reads the page as your browser rendered it, every element and the computed styles on each one, at every breakpoint you ask for, and rebuilds it as Gutenberg’s own native elements with the styles in Gutenberg’s own fields. It needs no access to your Shopify account, no export file and no API key. If Chrome can draw the page, wpgraft can copy it.
This is usually not a whole-store move. It is a marketing page, a landing page, a lookbook, an about page, that you want on WordPress without rebuilding it. wpgraft copies the rendered storefront section and lands it as core WordPress blocks. What does not come with it is anything that was Shopify doing work: cart, variants, checkout.