If the Magenta Pay Card is the only card stored in your Google Wallet, it will automatically be set as the default payment card. You can use the following steps to set your Magenta Pay Card as default if there are multiple cards already registered in your Google Wallet.
1. Launch the Google Pay app on your Android device.
2. Select the Magenta Pay Card.
3. Press the three dots in the upper right corner and then “Make default for tap to pay”.
4. Your Magenta Pay Card is now set as the default for transactions using Google Wallet.
Now, whenever you make a payment using Google Wallet, the Magenta Pay Card will be automatically selected.