<?php
    // Force la redirection vers HTTPS si la requête arrive en HTTP
    if (empty($_SERVER['HTTPS']) || $_SERVER['HTTPS'] === 'off') {
        header('Location: https://' . $_SERVER['HTTP_HOST'] . '/dashboard/', true, 301);
        exit;
    }

    // Si on est déjà en HTTPS, on va bien vers le dashboard sécurisé
    header('Location: https://' . $_SERVER['HTTP_HOST'] . '/dashboard/');
    exit;
?>
Something is wrong with the XAMPP installation :-(