To address the issue of the MyHyundai with Bluelink Apple Watch app not working, follow these detailed steps:

1. Log Out of the Bluelink App on Your Phone:
- Open the MyHyundai app on your iPhone.
- Navigate to the settings and find the option to log out.
- Log out completely before proceeding.

2. Open the Bluelink App on Your Apple Watch:
- On your Apple Watch, locate the Bluelink app and open it.
- You should see a prompt to log in.

3. Login to the App on Apple Watch:
- Do not close any notification that prompts you to log in on your watch. Follow the on-screen instructions to enter your credentials.
- If the app does not prompt you, try restarting your Apple Watch and then opening the app again to check if the prompt appears.

4. Check for Compatibility Issues:
- Confirm that your Apple Watch supports the MyHyundai with Bluelink app. There have been reports indicating that certain versions may no longer be compatible, and no updates for compatibility are expected - learn more - learn more.

5. Ensure Software Updates are Installed:
- Check if your iOS and watchOS are updated to the latest versions. Go to Settings > General > Software Update on your iPhone and watch.
- An outdated app or operating system can lead to functionality issues.

6. Reinstall the App:
- If the app continues not to respond, consider uninstalling and then reinstalling the MyHyundai with Bluelink app on your iPhone.
- Once reinstalled, repeat the login procedure in the app and try again on your Apple Watch.

7. Reset Connections:
- If issues persist, reset your Apple Watch's connections. You can do this by unpairing your watch from your iPhone and then pairing it again.
- Make sure to set it up as a new watch to avoid carrying over potential issues.

8. Consult the Community for Updates:
- Visit user forums such as Reddit or Hyundai-related forums to see if others are experiencing similar issues and to find any newly shared solutions - learn more - learn more.

By following these steps, you should be able to troubleshoot the problems you are facing with the MyHyundai with Bluelink app on your Apple Watch.