Uber api authentication, HTTP POST problem

hello there,
am trying to implement uber api in my app, starting with authentications, am getting an error as follow :

{"_body":{"isTrusted":true},"status":0,"ok":false,"statusText":"","headers":{},"type":3,"url":null} 

this is the block responsible for http :

     let headers = new Headers({
            'Content-Type': "application/x-www-form-urlencoded"
            });
            
            let options = new RequestOptions({ headers: headers });
            let data = `client_secret=${this.client_secret}&client_id=${this.client_id}&grant_type=authorization_code&redirect_uri=${this.redirect_uri}&code=${parameterMap.code}`;
            let jsonData = {client_secret:this.client_secret,client_id:this.client_id,grant_type:'authorization_code',redirect_uri:this.redirect_uri,code:parameterMap.code};

            return  this.http.post('https://login.uber.com/oauth/v2/token', data ,options)
                  .subscribe((data) => {
                    let respJson: any = data.json();
                    console.log(" sdsddsds");
                    console.log('respJson', respJson);
 
 this.storage.set(this.TOKENKEY, respJson.access_token);
 this.token = respJson.access_token; // load it up in memory
 observer.next(true);
 observer.complete();
 },(error)=>{console.log(JSON.stringify(error))});

anyone ? :no_mouth: , i tried using native http, and got an error as follow:

{"__zone_symbol__currentTask":{"type":"microTask","state":"notScheduled","source":"Promise.then","zone":"<root>","cancelFn":null,"runCount":0}}