How to get report from Firebase analytics using Firebase admin API

I am using node js Firebase SDK. How can I access analytics data from Firebase, with the help of Firebase admin API.

Solution

Update: there is now an API to get the Analytics reports data. See my answer here: Is there any api for dashboard analytics data?

You can also:

download the analytics report data from the Firebase console by clicking the Download CSV option from the ⠇ overflow menu. Also see my answer here: Is it possible to embed Firebase Analytics data from my apps into a webpage?
connect Firebase Analytics to BigQuery to export the raw events, and query them in BigQuery, or visualize them with Data Studio.