问Google函数/google库:无法读取未定义的属性“用户”

EN

const functions = require('firebase-functions'); // is installed automatically when you init the project
const { auth } = require('google-auth-library'); // is used to authenticate your request

async function exportDB () {
    const admin = await auth.getClient({
        scopes: [                               // scopes required to make a request
            'https://www.googleapis.com/auth/datastore',
            'https://www.googleapis.com/auth/cloud-platform'
        ]
    });
    const projectId = await auth.getProjectId();
    const url = `https://firestore.googleapis.com/v1beta1/projects/${projectId}/databases/(default):exportDocuments`;
    return admin.request({
        url,
        method: 'post',
        data: {
            outputUriPrefix: 'gs://name-of-the-bucket-you-created-for-backups'
        }
    });
}

gcloud functions deploy backup --runtime nodejs8 --trigger-topic YOUR_TOPIC_NAME_HERE