Hi, I have been putting the credential in the endpoint together which works fine for other api, i follows your way and put in the Headers Form now. But im getting the same response from shopify.
The key is already hidden at shopify admin panel, but I think i can confirm the key is correct as i use the same postman env for other API, like customer and product which return normal data.
Receiving the same response after putting the key in Headers Form.
Below is a product metafield api using the same postman environment
