can't set a default background for child themes

Hi

Could anyone provide me with information on how to create a default background/ background image for different themes. If I set a default background in the child themes css, users can’t change it in admin > appearance > background.

I currently don’t have a background set in my css and I’ve tried a few things such as-

$args = array(
	'default-color' => '000000',
	'default-image' => get_template_directory_uri() . '/images/background.jpg',
);
add_theme_support( 'custom-background', $args );

$defaults = array(
	'default-color'          => '000000',
	'default-image'          => '',
	'default-repeat'         => '',
	'default-position-x'     => '',
	'wp-head-callback'       => '_custom_background_cb',
	'admin-head-callback'    => '',
	'admin-preview-callback' => ''
);
add_theme_support( 'custom-background', $defaults );

Doing this sets the color ready in appearance > background. but not ready on the front-end, the backgrounds only appear when you go to the background backend and click save. Can I get a background or image on the front end straight away by default, thanks in advance.