我试图从云函数（Node. js）运行基于经典模板的数据流作业，并得到这个错误-当前用户不能充当服务号（xxx@yyy.iam.gserviceaccount.com）

var opts = {
            projectId: "project-id",
            location: "asia-south1",
            gcsPath: "gs://dataflow-templates/latest/Cloud_Bigtable_to_GCS_Avro",
            resource: {
                "jobName": "bt-backup-to-gcs-avro" + Date.now(),
                "environment": {
                    "bypassTempDirValidation": false,
                    "serviceAccountEmail": "xxx@yyy.iam.gserviceaccount.com",
                    "machineType": "n1-standard-8",
                    "tempLocation": "gs://some-bucket/some-dir",
                    "subnetwork": "subnetwork-val",
                    "network": "network-val",
                    "ipConfiguration": "WORKER_IP_UNSPECIFIED",
                    "additionalExperiments": []
                },
                "parameters": {
                    "bigtableProjectId": "project-id",
                    "bigtableInstanceId": "instance-id",
                    "bigtableTableId": "table-id",
                    "outputDirectory": "gs://some-bucket/some-dir",
                    "filenamePrefix": "table-backup-"
                }
            }
        };
        dataflow.projects.locations.templates.launch(opts, (err, result) => {
            if (err) {
                throw err;
            }
            console.log(result.data);
        });