@misc{ wiki:xxx, author = "Wikimedia Commons", title = "File:Coronet of a Child of the Sovereign.svg --- Wikimedia Commons{,} the free media repository", year = "2024", url = "https://commons.wikimedia.org/w/index.php?title=File:Coronet_of_a_Child_of_the_Sovereign.svg&oldid=868555879", note = "[Online; accessed 11-July-2024]" }
\usepackage{url}
somewhere in the preamble) which tends to give much more nicely formatted web addresses, the following may be preferred:
@misc{ wiki:xxx, author = "Wikimedia Commons", title = "File:Coronet of a Child of the Sovereign.svg --- Wikimedia Commons{,} the free media repository", year = "2024", url = "\url{https://commons.wikimedia.org/w/index.php?title=File:Coronet_of_a_Child_of_the_Sovereign.svg&oldid=868555879}", note = "[Online; accessed 11-July-2024]" }