It's asking me to call Monzo when I add my card to Apple Pay or Google Wallet

When you add your card to your phone's mobile wallet (Apple Pay or Google Wallet) - we require that your device's phone number matches the number on your Monzo account ☎️

If you recently got a new phone number, you might need to update your Monzo phone number to match. You can do that by tapping the profile picture on the top left of your app's home page.

After updating your phone number - you need to delete the Monzo card from your phone's wallet app, then re-add it 📱