I am developing a web app and I observe REST API standards. I am searching for REST API best practice for subscription and payments.

When a new user subscribe for "pro plan", user should pay money for plan and it is a transaction.

Should I set POST: users/{id}/subscriptions and SubscriptionsController@store when new user subscribes?

And because subscription is a transaction and 2 separated request (before/after bank), all of subscribe codes should be in SubscriptionController@store?

For upgrade, cancel or updating a plan should I set PUT: users/{id}/subscriptions/{id} and SubscriptionController@update or other endpoint?