在 Google Cloud Platform 控制台中将同意屏幕授权域添加为本地测试域。具体步骤如下：

1. 登录 Google Cloud Platform 控制台，进入对应的项目。
2. 选择“API 与服务” -> “凭据” -> 选择相应的客户端 ID。
3. 在“授权的 JavaScript 来源”和“授权的重定向 URI”中添加本地测试的 URL。
4. 在代码中使用授权的客户端 ID 和 secret 进行 Google 登录。

示例代码：

from google.oauth2 import id_token
from google.auth.transport import requests

# The CLIENT_ID and CLIENT_SECRET in the following code come from
# the API Console Credentials page:
#   https://console.developers.google.com/apis/credentials
CLIENT_ID = ''
CLIENT_SECRET = ''

# Use the following redirect URI when running the sample on your
# development server. After deploying your application to production,
# use your own URL.
REDIRECT_URI = 'http://localhost:8080/oauth'

# ...
auth_request = request('https://accounts.google.com/o/oauth2/auth', ...)
auth_response_text = auth_response.text
if 'accounts.google.com/o/oauth2/approval' in auth_response_text:
    # Send an empty POST request to the approval URL:
    approval_response = requests.post(auth_response.url, data={}, ...)
    # ...
# ...
if self.request.get('code'):
    # Exchange the authorization code for a refresh token and access token:
    authorization_code = self.request.get('code')
    credentials = flow.step2_exchange(authorization_code)
    userid = credentials.id_token['sub']
    # ...

其中，和需要替换为自己的客户端 ID 和 secret。= 'http://localhost:8080/oauth' 需要替换为自己的本地测试 URL。