Reference the advertisement according to the style for the source, i.e. an advertisement found in a journal, magazine or newspaper should be treated as much like an article from that source as possible.
If an advertisement does not have a title describe the advertisement in brackets, e.g. [Advertisement for the new Audi Q5].
(Friends of the Honey Bee, 2015)
Friends of the Honey Bee (2015)
Friends of the Honey Bee. (2015, May 4). Bee a hero: bee-come a friend and help get Britain buzzing again [Advertisement].
The Big Issue, 1152, 32.
1 Company followed by a full stop
2. Year, month date of publication in round brackets followed by a full stop
3. Title of the advertisement, or strapline, or slogan in italics
4. Advertisement in square brackets followed by a full stop
5. Title of the publication in italics followed by a comma, volume(issue number if there is one), page number(s) followed by a full stop
Nike. (2018, November 12). Dream crazy [Advertisement]. Youtube. https://www.youtube.com/watch?v=WW2yKSt2C_A
Company name. (Year, month date of upload). Title of the advert or strapline or slogan [Advertisement]. Platform. URL