By default, every synced Amazon order gets a Shopify order number (e.g., #1001, #1002). Turn this on to override that with the Amazon Order ID instead — making it easy to spot Amazon orders in Shopify and trace them back to Seller Central without copy-paste.
If you'd rather keep Shopify's default order numbering (e.g., #1001) but want a recognizable marker on Amazon orders, you can attach a Prefix and/or Suffix to the order name — generating IDs like EN1001-A.
EN), Suffix (e.g., -A), or both.#1001) itself can't be altered — only the prefix and suffix around it.