I am using Algorand blockchain for NFT transaction on mobile app. The app is in react native and on the app I am selling/buying NFT's. Apple rejected my app saying that I need to implement in-app purchases. How would I go about doing that? How to implement a cryptocurrency payment gateway? Does apple's in-app purchases support cryptocurrency payments?
I can't find any helpful resource to resolve this issue.
Apple's in-app purchases do not support cryptocurrency payments.
However, they do support cryptocurrency cards that are linked to Apple Pay. Lots of these exist, e.g. Coinbase. There are also rumours that AlgoFi may release one too.
The payment is converted into fiat before the transaction, so on your app it would be like handling a fiat payment. You can then theoretically use this fiat to buy $ALGO, and then use that for the transaction. The UX would ultimately look the same for the end user and it would seem like they are using the existing cryptocurrency in their wallet. But like a commenter said this is not reliable.
Apple does not allow apps that have any payments outside of their payment system. This means that currently an app cannot write to the blockchain at ALL unless payments and gas are relayed. You can work around this by developing an NFT marketplace app that allows users to view their NFTs and explore others, but if they want to do any transactions they are redirected to the mobile website.
So you have three options: trusting that the fiat is successfully taken out of the user's account and buying $ALGO, waiting for the payment to go through which means the transaction may take weeks, or directing to a website for all blockchain transactions.