Filter places available

add_filter(
	'wfea_availability_display',                         // filter hook name
	function ( $msg, $total_sold, $event_capacity ) {    // annonyous function that takes 3 parameters - paramters are defined by the hook
		if ( $total_sold >= $event_capacity ) {
			$msg = __( 'Sold Out', 'widget-for-eventbrite-api' );
		} else if ( ( $event_capacity - $total_sold ) > 10 ) { // set this number to what you like if you don't want a count
			$msg = 'Places Available';
		} else {
			$msg = sprintf( '%1$s Places Left', ( $event_capacity - $total_sold ) );
		}

		return $msg;   // the result return to the filter
	},
	10,     // the priority, so if multiple filters are called you can sequence
	3       //  the number of paramaters passed to the function
);