Ionic barcode sanner post reult

I create a small application that scans a qr code and sends the result of the qr code by post to an API.
There I managed to create the scanner of the qr code and I created I can post values on an API with ionic purpose I can’t send the result of the scanner.
Can anyone help me!

import { Component} from '@angular/core';
import { NavController } from 'ionic-angular';
import { Camera } from '@ionic-native/camera';
import { BarcodeScanner, BarcodeScannerOptions} from '@ionic-native/barcode-scanner';
import { HttpClient} from '@angular/common/http';
import { Observable } from 'rxjs/Observable';

  selector: 'page-home',
  providers: [Camera, BarcodeScanner],
  templateUrl: 'home.html',
export class HomePage {
  res: Observable<any>;
constructor(public camera:Camera,
    public barcodeScanner:BarcodeScanner,
    public navCtrl: NavController,
    public httpClient: HttpClient,
    public toast: Toast,) {}

    prompt:"Svp scanner le qr code",
  this.barcodeScanner.scan(this.option).then(barcodeData => {
    console.log(barcodeData); = barcodeData;
    var url = ''
    let postData = new FormData();
    postData.append('qrInfo', barcodeData);, postData).subscribe(barcodeData=>{
   }).catch(err => {
       console.log('Error', err);