Hi @adil ,
Sharepoint Designer 2013 is out of mainstream support since July 2021
Source: SharePoint Designer 2013
As far as I am aware of this is the latest update: August 2, 2016, update for SharePoint Designer 2013 (KB3114721)
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten