You will need:
Format:
Parliament. House of Commons (Year of publication) Title of bill. [Bills number]. Available from: www.webaddress.com [Accessed day month year].
Example:
Parliament. House of Commons (2013) Food labelling (sugar content). [Bill 23]. Available from: https://services.parliament.uk/bills/2013-14/foodlabellingsugarcontent.html [Accessed 28 January 2021].
In-text citation: (Parliament. House of Commons, 2013)