Retrieves an extended field by the specified extended field key.
Authentication
When developing websites or building an app with Blocks, this method may require elevated permissions, depending on the identity of the user calling it and the calling user’s permissions.
When building apps without Blocks or for headless projects, you can only call this method directly when authenticated as a Wix app or Wix user identity. When authenticated as a different identity, you can call this method using elevation.
Elevation permits users to call methods they typically cannot access. Therefore, you should only use it intentionally and securely.