https://wordpress.org/plugins/user-id-changer/

add_action( 'wp_head', 'my_popads_script' );

function my_popads_script(){

	if ( is_user_logged_in() ) {
		echo 'Welcome, visitor!';
	} else {
		?><script>popads code</script><?php
	}
};

<?php
if ( is_user_logged_in() ) {
    echo 'Welcome, visitor!';
} else {
    echo 'PopAds';
}
?>

https://wordpress.org/plugins/woo-prevent-cancel-order/