scopes aren't showing in response

[ManasaKalluri]

I am building a mobile app with react native which needs to access data from users fitbit devices. I am authorizing the user with outh2.0 and asking their consent for scopes. Till now, flow is working correctly, but I am getting a response with no scopes(general it will show the scopes which users checks or allows us to use) or empty scopes array (means users doesn't allow asked scopes even after users checks all the scopes) with an invalid access token. I tried doing it in web using same procedure and I am getting a response with scopes and access token correctly. why this happens in reactnative only ?or If anyone does it using RN please let me know the flow .

[ManasaKalluri]

This was the sample response {"accessToken": "eyJhbGciOiJIUzI1NiJ9.eyJhdWQiOiIyMkJXTDgiLCJzdWIiOiI4TUhUWUQiLCJpc3MiOiJGaXRiaXQiLCJ0eXAiOiJhY2Nlc3NfdG9rZW4iLCJzY29wZXMiOiJyYWN0IHJsb2MgcndlaSByaHIgcm51dCBycHJvIHJzbGUJleHAiOjE1OTgzNjYzMTgsImlhdCI6MTU5ODMzNzUxOH0.Oh2_Bxa", "accessTokenExpirationDate": "2020-08-25T14:38:36Z", "authorizeAdditionalParameters": {}, "idToken": null, "refreshToken": "882b6e6f68a4403f7ab714397e70b15d0112553a9be1d1a01af0b4f1c539d9ba", "scopes": [], "tokenAdditionalParameters": {"user_id": "XXXXXX"}, "tokenType": "Bearer"} & we used App Auth component