affwp_custom_wc_menu.php

<?php
/**
 * Adds "Affiliate Area" to WooCommerce's /my-account menu
 */
function affwp_custom_wc_menu( $items ) {
    
    // return if user is not an affiliate.
    if ( ! affwp_is_affiliate() ) {
        return $items;
    }
    
    // Remove the logout menu item, since we want this last.
    $logout = $items['customer-logout'];
    unset( $items['customer-logout'] );

    // Add the affilite area menu item.
    // Assumes that affiliate-area is the correct page slug of the Affiliate Area
    $items['affiliate-area'] = 'Affiliate Area';

    // Add back the logout menu item.
    $items['customer-logout'] = $logout;

    return $items;
}
add_filter( 'woocommerce_account_menu_items', 'affwp_custom_wc_menu' );