1. Managing Payment Methods on MacOS:

• To change or view your payment and shipping information associated with your Apple ID on a Mac, access the Apple menu.
• Select System Settings and click on your name at the top of the sidebar.
• Then, choose Payment & Shipping.
• If prompted, sign in with your Apple ID.
• Here, you'll see the payment methods associated with your Apple ID, such as credit cards, debit cards, or PayPal.
• You can add or remove payment methods as needed.

2. In-App Purchases on MacOS:

• When making in-app purchases, such as in Backgammon Masters, MacOS utilizes payment methods associated with your Apple ID.
• This includes nearly 200 different payment methods, including Apple Pay, credit and debit cards, store credit, region-specific methods, and more.
• These payment methods are securely stored and easily accessible when making a purchase.
• You can also view and manage all your subscriptions in one place, share eligible purchases through Family Sharing, and view your purchase history across all your Apple devices.

3. Using Apple Pay for In-App Purchases:

• If your Mac or Magic Keyboard has Touch ID, you can use Apple Pay for online purchases.
• Apple Pay can be set up by adding your preferred payment card to Wallet on your Mac.
• During checkout, select Apple Pay as your payment method and authenticate using Touch ID or your password.

By following these steps, you can easily manage your payment methods for in-app purchases on MacOS. For more detailed information, visit Apple's support pages on changing Payment & Shipping settings for your Apple ID on Mac and using Wallet & Apple Pay on Mac.