For those of you who may have missed the Translation Productivity Community Posting on Studio 2021.

If you install Studio 2021 SR1 you also need to download the latest WS Compatibility plugin (found on the Appstore - https://appstore.sdl.com/language/app/worldserver-compatibility-pack-for-sdl-trados-studio/1102/ ) in order to be able to work with WS packages in Studio.

Starting from SDL Trados Studio 2021, the WorldServer components - which include the ability to open and convert WSXZ packages, create WorldServer Return packages and use SDL Worldserver Translation Memories - are now included as a separate application that can be easily downloaded and installed from the App Store in SDL Trados Studio. The Worldserver components need to be installed once in order to be able to open WorldServer (*.WSXZ package). 

Attached is a KB article with steps.

https://gateway.sdl.com/apex/communityknowledge?articleName=000013233