How to buy Amazon Coins?

Could you please elaborate on the process of purchasing Amazon Coins? I'm interested in learning more about the steps involved, such as where to access the Amazon Coins option, how to select the desired amount, and what payment methods are accepted. Additionally, I'm curious about any potential discounts or promotions that might be available when purchasing Amazon Coins. Lastly, could you provide any insight into the benefits of using Amazon Coins for purchases on Amazon's platform? Thank you in advance for your assistance.