Hi! Looks like you're encountering an "HTTP verb used to access this page is not allowed" error when trying to top up your wallet in the DARB app on an Android device. I'd like to help you get this resolved.

To start, could you tell me a bit more about when this error occurs? For example:
- Are you using the latest version of the DARB app?
- Does this error appear immediately after you hit the top-up button, or after some processing?
- Have you tried this top-up on different networks (like switching from Wi-Fi to mobile data)?
- Is this happening with a specific payment method?

Generally, this error means that the app tried to communicate with the server using an HTTP method (like GET, POST, PUT) that the server doesn’t allow at that URL. It could be from an app bug, outdated version, or even an issue with app-server communication.

Here’s a step-by-step to troubleshoot:

1. Update the App: Make sure you have the latest version of the DARB app installed from the Google Play Store. Sometimes older versions may have fixed bugs.

2. Clear App Cache & Data:
- Go to Android Settings > Apps > DARB app.
- Tap on Storage.
- Clear cache first and restart the app. If the issue persists, try clearing data (note this may log you out).

3. Try a Different Network: Switch between Wi-Fi and mobile data to rule out network-related issues.

4. Reinstall the App: Uninstall and reinstall the DARB app to ensure a fresh start.

5. Check for Server Issues: Sometimes backend servers update their API restrictions. Is this issue affecting others too? You may check DARB's status page or community forums.

If all that is fine and the issue persists, it could be a server-side configuration problem or app bug that our developers might need to address.

Could you try these and let me know how it goes? If you’ve already tried any of these steps, please tell me which ones so I can suggest the next best action.