This plugin brings the power of the GraphiQL IDE to the WP-Admin.
Activate this plugin – with WPGraphQL (https://github.com/wp-graphql/wp-graphql) also active – and you will be able to browse your WPGraphQL schema straight from the WP-Admin.
Authentication works with your current session, so if you have proper permissions, you can run Mutations and Query for data that might be restricted to current users.