I will use the push function.
I would like to know the meaning of Active user.
If I sent to 100 users, each 50 times per month,
Is Active Users 5,000 ?
And if Max Active Users(100K) is over, How is the pricing(Indie)?
An active user is any user that makes API requests during that month.
In the scenario you suggested, if 100 users log in the app during one month (doesn't matter how many push notifications you send them), the active user count for your app will be 100 and not 5,000.
If you cross any of the limits for your indie account (number of users, data storage, etc.), Kinvey Sales team will get in touch to help you transition to the next pricing tier.