Monetization is only available with Stripe today. We chose Stripe as a payment provider as it is one of safest way to enable payments and billing. In case your country is not supported by Stripe right, you can try Stripe Atlas. This solution helps you launch your startup from anywhere in the world.
In the future, we also plan to introduce new payment providers. Feel free to let us know which one you would like to see implemented, from #general:feature-requests.