Hi there! I’m here to help you with the signing-in issue you're experiencing with the Walmart app. Let’s go through a few steps to figure this out.

1. Check Your Login Credentials: First, please ensure that you are using the correct email address or phone number tied to your Walmart account. Double-check for any typos in your username or password.

2. Reset Your Password: If you're unsure about your password, you can tap on the "Forgot Password?" option on the login page. This will allow you to reset it through your email. Make sure to check your email for the reset link, as it should have a code to get you back in1.

3. Clear App Cache: Sometimes, the app's cache may cause issues. To clear it:
- Go to Settings on your device.
- Tap Apps or Applications.
- Find Walmart in the list and tap on it.
- Select Storage and then tap on Clear Cache.

4. Reinstall the App: If the above steps don't work, you might want to try uninstalling and then reinstalling the Walmart app. This can refresh any corrupted files that could be causing login issues.

5. Check for Two-Step Verification: If you're trying to log in to the Me@Walmart app, be sure that you've signed up for two-step verification while on shift, as this is required for access1.

Please try these steps and let me know if they help resolve the issue! Are you satisfied with the solution I provided? If not, we can dig deeper into this problem together.