Auth0 Create rule save to db if user not found, else next

I am trying to create rule where I check if the user id is already in my database, if he is I want to continue, if not I want to send a post request with some data.

Now, I was able to do both separately but I don't know how to make this script working, even when the user.id is on my db, still tries to create it and I am getting mongodb error.

Can someone help me with the right code ?

 function (user, context, callback) {
   var baseURL = 'http://tttt.ngrok.io/api';
   var usr_id = new Buffer(user.user_id).toString('base64');
   var newUser = {
     'identity': {
       'user_email': user.email,
       'user_id': user.user_id
     }
   };
   var test = 'testtesttest';
   var getURL = baseURL + "/users/" + user.user_id;
   request.get({
     "url": getURL,
   },
   function(err, response, body) {
     if(response.body === 'null') {
       var putURL = baseURL + "/users/" + usr_id;
       request.post({
         "url": putURL,
         "json": newUser
       });
       console.log("user created" + usr_id);
       console.log(response.body);
     }
     if(err) return callback(err);
     console.log("user exist");
     return callback(null, user, context);
   });
 }

my simple backend code:

 router.post('/users/*', (req, res) => {
   User.create(new User({
     email: req.body.identity.user_email,
     authUserId: req.body.identity.user_id
   }))
   res.json(console.log("User Created"))
 })
 router.get('/users/:id', (req, res, next) => {
   User.findOne({authUserId: req.params.id}, (err, userr) => {
     if(err) {
       return next(err);
     } else if (userr) {
       res.json(userr.email);
     } else {
       res.json(null)
     }
   });
 });

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