How to get customer's client secret and which authentication type to choose ?

[sanmitha]

Can you explain me how to get user client secret and client id in order to call the oauth2/token and refresh token api which require the 
Server apps must pass an Authorization header with theirBasic Token, which is their Client ID and Secret formatted like so:"Basic " + base64encode(client_id + ":" + client_secret).
I need to capture user's fitbit data through my mobile app and backend server, for my app to access which type of application type should I choose ? 
If server side - how to get the client secret and client id ?

[JohnFitbit]

Hi @sanmitha, looks like you created a duplicate post. I'll be locking this one to keep our conversation limited to a thread.