Ionic-native post not working for native app like Android, but the it's working very in browser

 postHttp(req, data) {
    let d = new Date();
    const httpOptions = {
      headers: new HttpHeaders({
        'consumer-key': this.consumerKey,
        'consumer-secret': this.consumerSecret,
        'consumer-nonce': d.getTime().toString(),
        'consumer-device-id': 'device id of the app',
        'consumer-ip': '192.168.1.11',
      })
    };
    const nativeHeaders = {
      'Content-Type': 'application/json',
      'consumer-key': this.consumerKey,
      'consumer-secret': this.consumerSecret,
      'consumer-nonce': d.getTime().toString(),
      'consumer-device-id': 'device id of the app',
      'consumer-ip': '192.168.1.11',
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Methods': 'POST, GET, OPTIONS, PUT',
      'Accept': 'application/json'
    };
    return new Promise(resolve => {
      console.log('Check platform: ' + this.platform.is('[quote="BesaBoldwin, post:1, topic:199500, full:true"]
postHttp(req, data) {
    let d = new Date();
    const httpOptions = {
      headers: new HttpHeaders({
        'consumer-key': this.consumerKey,
        'consumer-secret': this.consumerSecret,
        'consumer-nonce': d.getTime().toString(),
        'consumer-device-id': 'device id of the app',
        'consumer-ip': '192.168.1.11',
      })
    };
    const nativeHeaders = {
      'Content-Type': 'application/json',
      'consumer-key': this.consumerKey,
      'consumer-secret': this.consumerSecret,
      'consumer-nonce': d.getTime().toString(),
      'consumer-device-id': 'device id of the app',
      'consumer-ip': '192.168.1.11',
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Methods': 'POST, GET, OPTIONS, PUT',
      'Accept': 'application/json'
    };
    return new Promise(resolve => {
      console.log('Check platform: ' + this.platform.is('cordova'));
      if (this.platform.is('cordova')) {

        this.httpNative.setDataSerializer('json');

        this.httpNative.post(this.url + req, data, nativeHeaders).then(resp => {
            // console.log(data.data);
            let d = JSON.parse(resp.data);
            // this.storeHttpData(request, d);
            resolve(d);           
          })
          .catch(error => {
            
          });

      }
      else {
        console.log('Data for Post: '+data);
        this.http.post(this.url + req, data, httpOptions).subscribe((data: any) => {
          resolve(data);
        }, (err) => {
          console.log('Error : ' + req, data);
        });
      }
    });
  }
      if (this.platform.is('cordova')) {
    this.httpNative.setDataSerializer('json');

    this.httpNative.post(this.url + req, data, nativeHeaders).then(resp => {
        // console.log(data.data);
        let d = JSON.parse(resp.data);
        // this.storeHttpData(request, d);
        resolve(d);           
      })
      .catch(error => {
            
          });

      }
      else {
        console.log('Data for Post: '+data);
        this.http.post(this.url + req, data, httpOptions).subscribe((data: any) => {
          resolve(data);
        }, (err) => {
          console.log('Error : ' + req, data);
        });
      }
    });
  }
Kindly help, Where am I going wrong?