I have questions on how to use billing API as follows.
1. Usage Charge a) Create a usage pricing plan b) Create a usage record - The usage record will automatically measure the usage of a merchant who installed my app and charge?
2. Active User based Charge - This type is not supported in billing API. - Is it possible to count a number of active users who are using my app and charge by using the other APIs on Shopify? - Or does my app need to count it by its own and how to charge it by billing API?