验证用户帐户后，刷新令牌为空

Question

我正在验证用户帐户并将详细信息写入json文件中以连接到云。如何获取刷新令牌

下面是我的代码，该代码执行身份验证并将详细信息存储在json

try:
    with open(file, 'r') as infile:
        creds = json.load(infile)
except FileNotFoundError:
    return ''
except json.decoder.JSONDecodeError:
    return ''

credentials = google.oauth2.credentials.Credentials(
    'access_token',
    refresh_token=creds['refresh_token'],
    token_uri=creds['token_uri'],
    client_id=creds['client_id'],
    client_secret=creds['client_secret'],
    scopes=creds['scopes'])

refresh_token = creds['refresh_token']
print(refresh_token)
return credentials

我的刷新令牌为空

{"refresh_token": null,
"token_uri": "https://oauth2.googleapis.com/token",
"client_id": "13465789222- 
tmd611m4j6ofdpsvp25t59s2gf6im4ed.apps.googleusercontent.com",
"client_secret": "HCdEIght0997j5iL2ewi2vUnM-", 
"scopes": ["https://www.googleapis.com/auth/cloud-platform"]}