quincenalmente - every two weeks, twice a month, fortnightlySpanish example: Suscríbete a cualquiera de nuestros diarios y obtén quincenalmente la Revista Cosas.
English example: Subscribe to any of our newspapers and obtain Cosas Magazine every other week.
Source: quincenalmente - every two weeks, twice a month, fortnightly (https://www.123teachme.com/spanish_feeds/word_of_the_day/2021/12/28)