When configuring using 'FileSource', how do I add a file with new data to reflect it?

I want to configure the feature store with an existing file and reflect it in the feature store when a new file is added.

I'm looking at several examples, but I can't find any of these examples.

I have a few questions regarding this.

1. When a new file is added, how do I add a new file while retaining the data of the existing file?

2. If question 1 is impossible, how can we add new data to the online store for new files?

Thank you for making a good library, and I look forward to a good answer.