Database Type didn’t show mssql option

Hello!
i am Rookie in wordpress ,there a problem when i install wordpress
i am using windows 10 ,i had install IIS,php manager and mssql, i followed the step from https://blog.rajenki.com/2012/12/wordpress-on-windows-server-2012-with-iis-8-and-sql-server-2012/
want to set up a web by using mssql but when i go to step one of setting wordpress i found my Database Type option only have PDO Mysql ,i don’t know what should i do now,please someone can help me?
thanks.