I would also like to add that in this tutorial:
https://shopify.dev/tutorials/manage-metafields-with-graphql-admin-api
updating metafields only exists for private metafields.
How about the public ones too? we need to access those fields in shopify liquid… We can’t use private metafields.
the POST of new public metafields works, but we need to UPDATE as well. When we try to do this with the public metafields this is thew error returned:
“Key must be unique within this namespace on this resource”.