How to access submitted form data value from request in ExpressJS

usersRouter.post('/:userId/bookmarks/upload', keycloak.protect(),  uploadBookmarks.single("bookmarks" /* name attribute of <file> element in your form */),  async (request, response) => {    userIdTokenValidator.validateUserId(request);    const userDisplayName = request.body.userDisplayName;    const importResponse = await browserBookmarksImportService.imporBrowserBookmarks(request.params.userId, request.file.buffer, userDisplayName);    const str = JSON.stringify(importResponse, null, 2); // spacing level = 2    console.log(str);    return response.status(HttpStatus.OK).send(importResponse);  });

  uploadBookmarks(userId: String, bookmarks: File, userDisplayName: string): Observable<any> {    const formData = new FormData();    formData.append('bookmarks', bookmarks);    formData.append('userDisplayName', userDisplayName);    return this.httpClient.post(`${this.usersApiBaseUrl}/${userId}/bookmarks/upload`, formData);  }