What software product should I use for subscriptions?

Question

Programming

You need to integrate with a service or several: -
you need to collect leads, store them in the database.
- send active messages, store information about the subscription to the service, after how long it will end, notify with messages.
- notification by SMS and Email is possible.
Maybe there are ready-made solutions, I've looked all over the Internet, I can't find what I like and performs all the functions.
Example: subscriptions to sports predictions.

Answer 1

What is arbitration?
Write yourself.
It will be better this way. Not easier, but better.