How to use multipart in ionic

Question

I am working on ionic 3 application. I have to send image on server. all is working fine but when i upload image it gives me internal server error. I want to send it by using multipart but unfortunately i don't know how to use it in ionic. I am so depressed. Any help would be appreciated. my upload code is as follow.

i have tried this code but unfortunatelly same error

saveMultipart(signupentries) {
 let url = this.baseUrl;
 url += "register1";
        const headers = {
          'enctype': 'multipart/form-data;',
          'Content-Type': 'application/json',
          'Accept': 'plain/text',
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Methods': 'POST, GET, OPTIONS, PUT',
}; const formData = new FormData();
        const dataJson = {
          'first_name': signupentries.first_name,
          'last_name': signupentries.last_name,
          'email': signupentries.email,
          'phone': signupentries.phone,
          'car_number': signupentries.car_number,
          'license_number': signupentries.license_number,
          'ownership_card': signupentries.ownership_card,
          'expiry_date_license': signupentries.expiry_date_license,
          'driver_picture': signupentries.driver_picture,
          'car_picture': signupentries.car_picture,
        };
        formData.append('dataJson', JSON.stringify(dataJson));
        return this.http.post(url,
            dataJson,
          {headers: headers});
    }

driverimage($event): void {
    this.file = $event.target.files[0];
    this.signupvm.driver_picture = this.file.name;
  }

in view side i am uploading like this as below

<ion-item>
        <ion-input
          type="file"
          placeholder="{{ 'driver_picture' | translate }}"
          accept="image/*"
          (change)="driverimage($event)"
        ></ion-input>
      </ion-item>