Add Login / Logout Links To The Custom Menu Area

functions.php

add_filter( 'wp_nav_menu_items', 'we_add_loginout_link', 10, 2 );
/**
 * Add login/logout and registration links to header menu
 *
 * @author Bruce Munson, WebEndev
 *
 */
function we_add_loginout_link( $items, $args ) {
    if (is_user_logged_in() && $args->theme_location == 'header') {
        $items .= '<li class="menu-item"><a href="'. wp_logout_url() .'">Log Out</a></li>';
    }
    elseif (!is_user_logged_in() && $args->theme_location == 'header') {
        $items .= '<li class="menu-item"><a href="'. site_url() .'/register/free-lifetime-membership/">Register</a></li>';
        $items .= '<li class="menu-item"><a href="'. site_url() .'/login/">Log In</a></li>';
    }
    return $items;
}

add_filter( 'wp_nav_menu_items', 'we_add_loginout_mobilelink', 10, 2 );
/**
 * Add login/logout, My Account, and registration links to mobile menu
 *
 * @author Bruce Munson, WebEndev
 *
 */
function we_add_loginout_mobilelink( $items, $args ) {
    if (is_user_logged_in() && $args->theme_location == 'mobile') {
        $items .= '<li class="menu-item"><a href="'. site_url() .'/account/">My Account</a></li>';
        $items .= '<li class="menu-item"><a href="'. wp_logout_url() .'">Log Out</a></li>';
    }
elseif (!is_user_logged_in() && $args->theme_location == 'mobile') {
        $items .= '<li class="menu-item"><a href="'. site_url() .'/register/free-lifetime-membership/">Register</a></li>';
        $items .= '<li class="menu-item"><a href="'. site_url() .'/login/">Log In</a></li>';
    }
    return $items;
}