How we can call GCP Composer DAG using http Request?

How we can call GCP Composer(Airflow) DAG using Http request. There is one way to call using google cloud function where we can do authenticate using iap.idToken. But instead of this do we have any other way like curl command or anything else.Here tricky part is, In airflow we can do because there is No authentication required but for GCP Composer we need to authenticate ??