Read Retention Label applied from sharepoint rest api

I am trying to read Retention Label applied using REST API but unable to read tried both values, tried CAML as well but not getting this field, can we read using API or is not possible?

_api/web/lists/getbytitle('documents')/items?$Select=OData__ComplianceTagWrittenTime

_api/web/lists/getbytitle('documents')/items?$Select=_ComplianceTagWrittenTime