redirect to post arguments

In function redirectIfNotMember() in npcms_membership.php the redirectToPost doesn’t work using the default permalink settings. Suggest fix from line 89

if ($restriction == 'member') {
                if (!$m->isUserLoggedIn()) {
                	wp_redirect(add_query_arg("redirectToPost", $post->ID, get_permalink($loginPageId))); exit;
                    //wp_redirect(get_permalink($loginPageId).'?redirectToPost='.$post->ID); exit;
                }
                return;
            }

            if ($restriction == 'member-roles')
            {
                if (!$m->isUserLoggedIn()) {
	                wp_redirect(add_query_arg("redirectToPost", $post->ID, get_permalink($loginPageId))); exit;
                    //wp_redirect(get_permalink($loginPageId).'?redirectToPost='.$post->ID); exit;
                }

                if (!$m->userInRole($selectedRoles)) {
                	wp_redirect(add_query_arg("unauthorized", "true", get_permalink($loginPageId))); exit;
                    //wp_redirect(get_permalink($loginPageId).'?unauthorized=true'); exit;
                }
                return;
            }

https://wordpress.org/plugins/membership-with-imis-and-membercms/