I don't speak Japanese, but I found your question when I encountered the same problem. The working HTML is as follows:
<!doctype html>
<html>
<head>
<title>Datastore and Firebase Auth Example</title>
<script src="{{ url_for('static', filename='script.js') }}"></script>
<link type="text/css" rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
<script src="https://www.gstatic.com/firebasejs/9.13.0/firebase-app-compat.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.13.0/firebase-auth-compat.js"></script>
<script src="https://www.gstatic.com/firebasejs/ui/6.0.1/firebase-ui-auth.js"></script>
<link type="text/css" rel="stylesheet" href="https://www.gstatic.com/firebasejs/ui/6.0.1/firebase-ui-auth.css" />
<script>
const firebaseConfig = {
apiKey: "--redacted--",
authDomain: "--redacted--",
projectId: "--redacted--",
storageBucket: "--redacted--",
messagingSenderId: "--redacted--",
appId: "--redacted--"
};
firebase.initializeApp(firebaseConfig);
</script>
</head>
<body>
<h1>Datastore and Firebase Auth Example</h1>
<div id="firebaseui-auth-container"></div>
<button id="sign-out" hidden=true>Sign Out</button>
<div id="login-info" hidden=true>
<h2>Login info:</h2>
{% if user_data %}
<dl>
<dt>Name</dt><dd>{{ user_data['name'] }}</dd>
<dt>Email</dt><dd>{{ user_data['email'] }}</dd>
<dt>Last 10 visits</dt><dd>
{% for time in times %}
<p>{{ time['timestamp'] }}</p>
{% endfor %} </dd>
</dl>
{% elif error_message %}
<p>Error: {{ error_message }}</p>
{% endif %}
</div>
</body>
</html>
バッドをするには、ログインかつ
こちらの条件を満たす必要があります。