WordPress facebook login in Android app

I am currently developing an app interact with word press service. And when I tried to call facebook connect in my application via word press user api, it gives error. Here is how I did:

First I connect my facebook account with permissions to get the access token. This step is success and the token is valid here. I have tried to use this token to get user profile with facebook “/me?fields=id,name,email”, it returned correct data.

        mFacebookCallbackManager = CallbackManager.Factory.create();

        btnFacebookSignIn.setReadPermissions("public_profile", "user_friends", "email");
        btnFacebookSignIn.registerCallback(mFacebookCallbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                handleFacebookLoginSuccess();
            }

            @Override
            public void onCancel() {
            }

            @Override
            public void onError(FacebookException error) {
            }
        });

Then I use the token to connect facebook with word press service:

URL: http:///api/user/fb_connect/?access_token=

Json returned: {“status”:”ok”,”msg”:”Your ‘access_token’ did not return email of the user. Without ’email’ user can’t be logged in or registered. Get user email extended permission while joining the Facebook app.”}

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Note:

• I have included “email” permission above and can get the email field via “/me”.

• You can see details of facebook connect in word press here https://wordpress.org/plugins/json-api-user/

Any suggestions will be appreciated. Thanks