Adding a policy to my graphql resolver

[commentsBot]

I did it like this way in register

module.exports = (strapi) => {
  const extensionService = strapi.plugin("graphql").service("extension");

  // read-single policy for letter
  extensionService.use(({ nexus }) => ({
    resolversConfig: {
      "Query.post": {
        policies: ["api::post.can-read"],
      },
    },
  }));
};