Changes to Directive 2009/73/EC of the European Parliament and of the Council of 13 July 2009 concerning common rules for the internal market in natural gas and repealing Directive 2003/55/EC
EU Directive 2009/73
Made by Regulation (EU) 2018/1999 on the Governance of the Energy Union and Climate Action
From legislation.gov.uk's record of changes, the official one: see it there.