Charging for digital goods in Google Docs Addon (apps script) now that Wallet for digital goods is retired?

Any tips for charging for digital goods now that Google Wallet for digital goods is retired? https://support.google.com/wallet/business/answer/6107573 Could we use the Chrome Web Store API? https://developer.chrome.com/webstore/payments-iap

Romain Vialard has monetized one of his add-ons using PayPal, you could take a look at that.