Help in post to drupal

Ionic Framework ionic-v3
1

hello

how are you ?

i’m new in ionic and javascript so i have json file from drupal8 and this some of content in the json file

[
    {
        "title": "اختناق مروري",
        "field_case_details": "<p>حالة اختناق مروري في منى</p>\n",
        "field_hajj_program_number": "<a href=\"/taxonomy/term/2\" hreflang=\"en\">حملة عون</a>",
        "field_image": "http://54.161.232.107/sites/default/files/styles/thumbnail/public/2018-08/%D9%83%D9%8A%D9%81_%D8%AA%D8%A4%D8%AF%D9%8A_%D9%85%D9%86%D8%A7%D8%B3%D9%83_%D8%A7%D9%84%D8%AD%D8%AC_4.jpg?itok=v92JBHqG",
        "field_location": "منى-مكة",
        "field_name": "سلمى",
        "field_phone_number": "<a href=\"tel:058421658\">058421658</a>"
    },

and i use this code in ts file for get method and it work and bring the content to me

export class LostPage {

  public items:any;
  constructor(public navCtrl: NavController, public http: HttpClient) {
   this.getData();
  }

  getData(){
    let url='MyJsonURl';
    let data: Observable<any> = this.http.get(url);
    data.subscribe(result =>  {
      this.items = result;
    });
  } 

}

and now i want to post content form ionic to drupal i make this html code

    <form (ngSubmit)="PostData()">
      <ion-item>
        <ion-label>title</ion-label>
        <ion-input type="text" [(ngModel)]="title" name="title"></ion-input>
      </ion-item>
      <ion-item>
        <ion-label>field_case_details</ion-label>
        <ion-input type="text" [(ngModel)]="field_case_details" name="case_datails"></ion-input>
      </ion-item>
      <ion-item>
        <ion-label>field_location</ion-label>
        <ion-input type="text" [(ngModel)]="field_location" name="loaction"></ion-input>
      </ion-item>

      <button ion-button type="submit" block>add content</button>

    </form>

and this code in ts file

export class AddtrafficPage {

  public items:any;
  title: any;
  field_case_details: any;
  field_location: any;
  mydata: any;
  constructor(public navCtrl: NavController, public http: HttpClient , public restProvider: ResolvedReflectiveProvider) {
   this.PostData();
  }

  PostData(){
    let postParams =  {
    "title": this.title,
    "case_datails": this.field_case_details,
    "loaction": this.field_location
  } 
  
  this.http.post("MyjsonURL",JSON.stringify(postParams))
    .subscribe(data => {
      this.PostData =data.json()
      let response = this.mydata.code;
      alert(response);

    }, error => {
      
      // Error getting the data
      console.log(error);
    });
}

}

but when i click on submit button no thing happen can you help me to post what i wrote in ionic to drupal and for your knowledge i gave permission for any one to add content in drupal

thanks