How to display the widget function?

If the widget function is not displayed in the WordPress backend, most likely the theme does not support it. This does not mean that you can not teach it to the respective theme.

Solution: For this, the following code is inserted into the functions.php.

function ourWidgetsInit(){
  register_sidebar( array (
    'name' => 'Sidebar',
    'id' => 'sidebar1'
  ));
}
add_action('widgets_init', 'ourWidgetsInit');