Не получается загрузить файл на сервер

import { Component, OnInit } from '@angular/core';
import { HttpClient, HttpEventType } from '@angular/common/http';
 
@Component({
  selector: 'add-file',
  templateUrl: './add-files.component.html',
  
})
 
export class AddFilesComponent implements OnInit {
 
  fileData: File = null;
  previewUrl: any = null;
  fileUploadProgress: string = null;
  uploadedFilePath: string = null;
  constructor(private http: HttpClient) { }
 
  ngOnInit() {
  }
 
  fileProgress(fileInput: any) {
    this.fileData = <File>fileInput.target.files[0];
    this.preview();
  }
 
  preview() {
    // Show preview 
    var mimeType = this.fileData.type;
    if (mimeType.match(/image\/*/) == null) {
      return;
    }
 
    var reader = new FileReader();
    reader.readAsDataURL(this.fileData);
    reader.onload = (_event) => {
      this.previewUrl = reader.result;
    }
  }
 
  onSubmit() {
    let formData = new FormData();
    formData.append('files', this.fileData);
 
    this.fileUploadProgress = '0%';
 
    this.http.post('http://localhost:5000/api/file/addfile', formData, {
      reportProgress: true,
      observe: 'events'
    })
      .subscribe(events => {
        if (events.type === HttpEventType.UploadProgress) {
          this.fileUploadProgress = Math.round(events.loaded / events.total * 100) + '%';
          console.log(this.fileUploadProgress);
        } else if (events.type === HttpEventType.Response) {
          this.fileUploadProgress = '';
          console.log(events.body);
          alert('SUCCESS !!');
        }
 
      }) 
  }
}