How do I set it up?

Install Granite from the Shopify App Store. It is free on Shopify.

Open the app in your Shopify admin and choose Connect your Granite account.

A Granite page opens. Sign in (or sign up) and pick your own account or a workspace you administer.

Granite creates the vault "Store name (Shopify)" there and starts the import. Large catalogs take a few minutes.