A. 1. Check Credentials: Ensure you are entering the correct username and password. If you’ve forgotten your password, use the 'Forgot Password' feature to reset it. 2. Update the App: Make sure you are using the latest version of the app, as updates may fix authentication bugs.

B. 3. Clear App Cache: Go to Settings > General > iPhone Storage > Circle K. Tap 'Offload App' to clear the cache, then try logging in again.