Hi there! I understand you're having trouble with the biometric sign-in feature on the SmartRewards app on your Android device. I'd like to help you get that working.

First, could you tell me a bit more? For example:
- Does the biometric option show up at all when you try to sign in?
- Have you used biometric login successfully before on this device?
- Have you recently updated the app or your device?
- Are other apps on your device recognizing your fingerprint or facial recognition correctly?

This info will help me narrow down the issue. Meanwhile, here's a simple checklist to try:

1. Make sure your device’s fingerprint or face recognition is set up correctly in your Android device settings. You can check this under Settings > Security > Fingerprint or Face.
2. Confirm that the SmartRewards app has permission to use biometric data. Go to Settings > Apps > SmartRewards > Permissions and see if biometric access is allowed.
3. Restart your phone to refresh system settings.
4. Try logging in again using biometric sign-in.

If these don’t work, uninstalling and reinstalling the SmartRewards app can help clear any app-specific glitches, but I want to check what you've tried before suggesting that.

Let me know how it goes or if you’ve already attempted any of these steps!