[Vuejs]-How can i order a snapshot value in timestamp order?

Firestore can only order/filter data on values that it has indexes for. While it may also store additional metadata for its own purposes, this values are typically not indexed (the document ID being the one exception to that), and thus can’t be used in queries.

Thus there is no way to order Firestore results based on the internal timestamp. If you want to be able to order documents on a timestamp, you’ll have to store that timestamp as a field in the document, and then pass that field name to orderBy.