You can ask Fandom support, but they will not give you a WR unless your wiki is based on a popular topic, preferably a game or entertainment show, and has a high volume of traffic and viewer volume. The chances of getting a WR for a fan fiction wiki are quite low, to be honest.
Also just be aware that a WR isn't doing anything in place of admins and editors. They do things that admins cannot do, such as editing certain MediaWiki messages. Little wikis would gain nothing from having a WR.