how to use fxml files in javafx code example

Example: javafx application fxml

FXMLLoader loader = new FXMLLoader();
loader.setLocation(Main.class.getResource("Path/To/file.fxml"));
root = loader.load();

Scene scene = new Scene(root, width, height);
primaryStage.setScene(scene);

primaryStage.setTitle("Title");
primaryStage.show();