WC Points & Rewards Filters

Hi,

I’m looking to create a filter that alters the text displayed at the checkout page depending on whether a user is logged in or not. If not, they are suggested to login in order to qualify for the points.

PHP isn’t my strong point – this is what I’ve come up with so far but doesn’t work. If someone could point me in the right direction it would be greatly appreciated.

apply_filters ( 'wc_points_rewards_earn_points_message', $message, $points_earned );
function points_rewarded_message($message) {
	if(is_user_logged_in()) {
		return "Complete your order and earn {points} points for a discount on a future purchase";
	} else {
		return"Please login to qualify for your Cavendish Points";
	}
}

Thanks,

Joe