I am currently working on an authentication pipeline that has a similar process to OAuth.

If authentication is successful in the third-party authentication system, the value will be transferred to Success Direct url, which I want to communicate with my server to configure to proceed with self-authentication.

In this situation, I organized the api of the success redirect url into lambda and used Lambda's callback object to process responses and requests in a chain.

But the code below always returned the null value, and I have no idea why.

```
// index.js
const Auth = require('AuthRequest')

exports.handler = async function (event, context, callback) {
    if (event.routeKey == 'POST /authentication/success') {
        var body = Auth.parse_query_to_json(Auth.decode_base64(event.body));

        if (body.resultCode == '0000') {        // success
            await Auth.get_auth_info(body, callback);
        }
        else {                                  // failure
            callback(null, {
                statusCode: 200,
                body: 'failure1'
            });
        }
    }
    else if (event.routeKey == 'POST /authentication/failure') {
        callback(null, {
            statusCode: 200,
            body: 'failure2'
        });
    }
};

```

```
// authRequest.js
const superagent = require('superagent')

var get_auth_info = async function (body, callback) {
    await superagent
        .post(url)
        .send({
            ...
        })
        .set('Content-Type', 'application/json;charset=utf-8')
        .end(async function(err, res) {
            if(err) {
                callback({
                    statusCode: 200,
                    body: 'failure3'
                });
            }
            else {
                callback(null, res)
            }
        });
};

var create_user_auth = async function (req, callback) {
    await superagent
        .post('my-auth-api-uri')
        .send({
        })
        .set('Content-Type', 'application/json;charset=utf-8')
        .end(async function(err, res) {
            if(err) {
                callback({
                    statusCode: 200,
                    body: 'failure4'
                });
            }
            else {
                if(res.status == 200) {
                    callback(null, res)
                }
                else {
                    callback({
                        statusCode: 200,
                        body: 'failure5'
                    });
                }
            }
        });
};

......

```

And this lambda funciton is triggered by a API Gateway and uses the event object of Payload 2.0 version using http api.

Is there anyone who knows the answer to this question?