wp_enqueue_script was called incorrectly

To solve this issue I’ve replaced

if ( is_admin() ) {
	wp_enqueue_script('javascript', get_bloginfo('url').'/wp-content/plugins/dashboard-maintenance-mode/script.js');
}

with

function enqueue_scripts()
{
	if ( is_admin() ) {
		wp_enqueue_script('javascript', get_bloginfo('url').'/wp-content/plugins/dashboard-maintenance-mode/script.js');
	}
}
add_action('admin_enqueue_scripts', 'enqueue_scripts');

https://ww.wp.xz.cn/plugins/dashboard-maintenance-mode/