I can't get the image object angular file uploader library

Question

I'm using https://www.npmjs.com/package/angular-file-uploader and I can't get the image object in the documentation of the library doesn't has anything about get the object of the image.

<angular-file-uploader #fileUpload1 [config]="afuConfig" [resetUpload]=resetVar (ApiResponse)="upload($event)">
</angular-file-uploader>




upload(img)
{
 // let data = img.response;
  this.book.image = img.response;
  console.log(this.book.image);
}







 this.afuConfig = {
    multiple: false,
    formatsAllowed: ".jpg,.png",
    maxSize: "3",
    uploadAPI:  {
      url:'http://localhost:3999/admin/' +'upload-avatar',
      method:"PUT",

      responseType: 'json',
    },
    theme: "dragNDrop",
    hideProgressBar: true,
    hideResetBtn: true,
    hideSelectBtn: true,
    fileNameIndex: true,
    replaceTexts: {
      selectFileBtn: 'Select Files',
      resetBtn: 'Reset',
      uploadBtn: 'Upload',
      dragNDropBox: 'Drag N Drop',
      attachPinBtn: 'Attach Files...',
      afterUploadMsg_success: 'Successfully Uploaded !',
      afterUploadMsg_error: 'Upload Failed !',
      sizeLimit: 'Size Limit'
    }
};

what must I put in upload() to get the image object and convert it to json. the backend is done in nodejs.