From FCM console I can not set up much more than 10 recurring notifications.
You can have up to 10 unique recurring notifications active per project
I want to aim targeting audiences, user properties, last user engagement also. For example, you can set up a recurring notification that sends a push notification to a user who has been inactive for 2 days. From FCM console it is possible but I want to set it up manually since FCM console does not allow me to create recurring notifications much more than 10.
There is no API to create recurring notifications in Firebase Cloud Messaging. Since you already tagged your question with google-cloud-functions
, you seem to know that you can create scheduled tasks with that.
To create a scheduled, recurring notification you can:
From this documentation and the examples in it, you should be able to get the use-case working. If not, post another question with the minimal, complete code that any of us can run to reproduce where you got stuck.