How to Hide AWS SNS Plugin Admin Menus

function plt_hide_aws_sns_menus() {
	//Hide the "Settings → AWS SNS" menu.
	remove_submenu_page('options-general.php', 'aws-sns_settings');
	//Hide the "AWS SNS" menu.
	remove_menu_page('aws-sns_backend');
}

add_action('admin_menu', 'plt_hide_aws_sns_menus', 11);

Where do I put this code?