Look through the available updates and add-ons listed for your installed AutoCAD 2021 software.
One AutoCAD license covers all language variations on that machine. System Requirements and Prerequisites Language Pack Autocad 2021
A: The standalone software is a full installation of AutoCAD that includes a single, default language. A language pack is an add-on module added to an existing installation to add support for an additional language. Look through the available updates and add-ons listed