Make auth ionic 3 with laravel api and with barryvdh/laravel-cors

ı had some error about signup but then ı installed this composer require barryvdh/laravel-cors

and add this line to app/Http/Kernel.php

protected $middleware = [
    // ...
    \Barryvdh\Cors\HandleCors::class,
];

its worked for auth(ı mean post method) but then after ı installed this package get method not worked( for giving info; before making this installing my get method worked very well). so please help me ; how can ı make work get method.

signup.ts

export class SignUpPage {
  responseData : any;
  userData = {"full_name":"", "password":"","email":"","name":""};

  signup() {
    if(this.userData.full_name && this.userData.password && this.userData.email && this.userData.name){
      //Api connections
    this.authProvider.postData(this.userData, "signup").then((result) =>{
    this.resposeData = result;
    if(this.resposeData.userData){
      console.log(this.resposeData);
      localStorage.setItem('userData', JSON.stringify(this.resposeData) )
      this.navCtrl.push(HomePage);
    }
    else{
      this.presentToast("Please give valid username and password");
    }

    }, (err) => {
      console.log("this error: "+ JSON.stringify(err));
    });
  }
  else {
    console.log("Give valid information.");
  }

  }

auth service

postData(credentials, type){

    return new Promise((resolve, reject) =>{
      let headers = new Headers({
        'Content-Type' : 'application/json'
      });
      let options = new RequestOptions({ headers: headers });



    this.http.post(apiUrl, JSON.stringify(credentials), {headers: headers}).
      subscribe(res =>{
        resolve(res.json());
      }, (err) =>{
        reject(err);
      });

    });