<param name="url_exit" value="./">

/?password=password

Neo.handleExit = () => {
    <?php if($rep): ?>
    const formData = new FormData();
    formData.append("pwd", "パスワード"); 

    fetch("./", {
        method: 'POST',
        mode: 'same-origin',
        body: formData
    })
    .then(response => {
        if (response.redirected) {
            //レスポンスのリダイレクトを検出して移動
            return window.location.href = response.url;
        } else {
            console.error('There was an error with the fetch operation:', response);
            throw new Error('Fetch operation failed');
        }
    })
    .catch(error => {
        console.error('There was a problem with the fetch operation:', error);
    });
    <?php else: ?>
    return window.location.href = "./";
    <?php endif; ?>
}

<param name="url_exit" value="./">