I'm learning Flutter application development and I have been faced with a major issue of how to save multiple files uploaded from the phone to the WordPress website through rest API. I have captured the files through Flutter as shown by the following code. void saveCheckIn() async { if (_image.length > 6) { Toasts.show("Upload a max of 6 IMAGES"); return; } final formData = FormData.fromMap({ 'name': 'dio', 'date': DateTime.now().toIso8601String(), }); for (var imageFile in _image) { formData.files.addAll([ MapEntry("images[]", await MultipartFile.fromFile(imageFile.path)), ]); } Dio dio = Dio(); dynamic headers = { "Accept": "application/json", "Content-type": "application/json" }; try { BuildContext showDialogContext = Toasts.showLoading(context: context); var response = await dio.post( "${Constants.baseUrl}/clients/checkin", options: Options( headers: headers, ), data: formData, ); Navigator.of(showDialogContext).pop(); print(response.data.toString()); } catch (e) { Toasts.show("Error: $e"); } } From the above dart code, _image is a List containing all the image files I'm not sure how to receive those images through WordPress REST API. I have tried to do research but I can't find anything helpful. This is my WordPress Code add_action( 'rest_api_init', 'wpmam_rest_user_endpoints' ); function wpmam_rest_user_endpoints( $request ){ register_rest_route( 'wp-mobile-app-manager/v2', "clients/checkin", array( "methods" => array( "POST", "GET", "PUT", "DELETE", "PATCH" ), "callback" => "wpmam_mobile_app_checkin_clients" ) ); } function wpmam_mobile_app_checkin_clients($request){ $response = array(); $parameters = $request->get_json_params(); $username = $parameters['username']; $password = $parameters['password']; $name = $parameters['name']; $date = $parameters['date']; $images = $parameters['files']['images']; // NOT SURE IF THIS IS CORRECT foreach ($images as $key => $value) { // NOT SURE HOW TO MOVE ON } wpmap_upload_files( $request = null, $user_id = 0 ); return new WP_REST_Response( $response, 123 ); }