Hi there! I see you're encountering the "Service Temporarily Unavailable" message in the Global Smart Plus app when trying to use the FD feature. Let's work through this together.

First, can you tell me if this issue happens consistently every time you try to use FD, or is it intermittent? Also, have you checked if your internet connection is stable when this occurs?

In the meantime, here are some initial steps to try:

1. Restart the Global Smart Plus app completely (close it from the app switcher and reopen).

2. Ensure your iPhone is connected to a stable Wi-Fi or cellular data network.

3. Restart your iPhone to clear temporary glitches.

4. Check if there’s any available update for the Global Smart Plus app in the App Store and install it if so.

If these steps don’t resolve the issue, the "Service Temporarily Unavailable" message often points to a server-side problem or connectivity issue with the app's backend services. I’d also recommend:

- Logging out of the app and logging back in to refresh your session.

- If possible, trying the FD feature at a different time to see if it is a temporary server downtime.

If the problem persists, it could be related to a server error or an unknown internal issue (somewhat like tax terminal errors noted with similar messages in other contexts1). In that case, I can assist in escalating the issue to our backend support team for a deeper look.

Could you please try the steps above and let me know how it goes? Also, if you’ve already tried some of these, let me know which ones so I can tailor my next suggestions.