UK BEIS have not yet issued final guidance on the format of the required declaration of conformity but below are links to current UK Government Guidance:

• Placing manufactured goods on the market in Great Britain from 1 January 2021
• Using the UKNI marking from 1 January 2021
• Meeting climate change requirements from 1 January 2021
• Regulations: energy information

As soon as guidance on the UK Declaration is published we’ll provide more information here