Download the Walmart app from the App Store or Google Play
Open the app and sign in to your Walmart account
Tap the account or menu icon
Select Walmart Pay
Add a payment method if prompted
Enter your card details or choose a saved payment method
Verify your payment method if required
Set up a PIN or security option if prompted
At checkout, open Walmart Pay in the app
Scan the QR code at the register
Confirm the payment to complete the purchase