How to do a firestore query in chronological order on creation
Unfortunately, Cloud Firestore auto-generated IDs do not provide any automatic ordering, and cannot be relied-upon to be chronological. To order your documents chronologically, you should add your own timestamp field to the documents.
From the Firestore add a document documentation:
Important: Unlike "push IDs" in the Firebase Realtime Database, Cloud Firestore auto-generated IDs do not provide any automatic ordering. If you want to be able to order your documents by creation date, you should store a timestamp as a field in the documents.