422 Unprocessable Entity when using request proxy

Hello,

I am following the guidelines provided at https://developer.zendesk.com/documentation/apps/app-developer-guide/making-api-requests-from-a-zendesk-app/#using-a-third-party-oauth-access-token and every time i try to perform a request using the proxy i get a HTTP 422 Unprocessable Entity error.

My App has successfully completed the OAuth setup (i use Okta as the OAuth provider)  and i am trying to make a simple call to my backend.

const options = {
  url: "https://api.example.com/list",
  type: "GET",
  headers: {
    Authorization: "Bearer {{setting.token}}",
  },
  secure: true,
};
await this._client.request(options);