If no person is named, use the government agency or department as a group author.
The style does require that the author and publisher should be recorded as they appeared when the document was published, whether in print or online – not amended to their current title.
In-text citation
(Department of Health, 2017)
Reference List
Department of Health. (2017). Tobacco free Ireland annual report 2015.
https://health.gov.ie/wp-content/uploads/2017/03/Tobacco-Free-Ireland-Annual-Report-2015.pdf