Default Theme Background Image (Hook)

When using LoginPress on the multisite setup you may require to change the default LoginPress theme background image. The following filter will help you achieve the task
add_filter( 'loginpress_default_bg', 'loginpress_default_bg_callback' );

function loginpress_default_bg_callback( $background ) {

$background = 'https://cdn.pixabay.com/photo/2019/07/19/09/40/flowered-balloon-flower-4348351_960_720.jpg';

return $background;

}

Here $background contains the URL for the background image. Make sure the image is optimized, otherwise it can cause the login page to load slow.