The volume to which an article belongs is determined by the date of acceptance, rather than the date of publication (e.g. the article accepted 11 December 2020 and published 29 January 2021 belongs to volume 2, rather than volume 3)
Articles within each volume have consecutive numbering, based on date of acceptance, up to volume 2, article 41 (11 September 2020), after which individual articles are given six digit numbers corresponding to the article's doi (e.g. volume 2, article 546917 (19 October 2020))