Response for preflight has invalid HTTP status code 404 in ionic 3

Question

Getting error Response for preflight has invalid HTTP status code 404 on one of my api. Because of this the post method get converted into option method.

To solve this added options in my authservice below is my code.

      securePostData(credentials, type){

    return new Promise((resolve, reject) =>{

     var token= JSON.parse(localStorage.getItem('userStorage')).token;
     // let headers = new Headers();
/*      let headers = new Headers();
      headers.append('Content-Type', 'application/x-www-form-urlencoded');
      headers.append('Authorization', 'bearer '+token);
      headers.append('Access-Control-Request-Methods', 'post');*/
      let headers = new Headers({ 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
                                  'Authorization': 'bearer '+token,
                                  'Access-Control-Request-Methods':'post',
       });
      let options = new RequestOptions( {method: RequestMethod.Post, headers: headers });


      console.log(credentials);

      this.http.post(apiUrl+type, credentials, options).
      subscribe(res =>{
        console.log(res);
        if(res.status == 200) {
          resolve(res.json());
        } else {
          alert('Something went wrong');
        }
      }, (err) =>{
        if(err.status == 401 || err.status == 400) {
          var er = JSON.parse(err._body).error;
          console.log(er);

       let toast = this.toastCtrl.create({
        message: er,
        duration: 3000,
        position: 'bottom'
      });

      toast.onDidDismiss(() => {
        console.log('Dismissed toast');
      });

      toast.present(); 
        }
        /*console.log('gfx');
        console.log(err);*/
        reject(err);
      });

    });

  }

I also added url of my api website in proxies url in my ionic.congfig.json but still not working