I want to use this API on Android Please help me

I was going to search by myself, but it's really hardThis is

I'll try to write the code while studying by myself

Please search by which keyword and tell me which part of API I can use Please

https://dev.fitbit.com./build/reference/web-api/

I'm trying to make an Android application using this OAPI

It's a company called Fitbit that makes smart bands.

I would like to create an application that can receive sleep information stored on the fitbit.com server

I think I'm only searching for a week, but I've tried this and that, but nothing works

As far as I understand,

1. Obtain OAuth 2 certification.

2.https://api.fitbit.com/1.2/user/[user-id]/sleep/date/[date].json I get this form of http and parse it.

I think this is how it works

I don't know how to do it from number one.ㅠ<

I would appreciate it if anyone could take a look at it and let me know if I could do it like this would be a great help!