Problem installing Record source TU 2021

Hello,

I just upgraded from Studio 2019 to Studio 2021 and I realized that the Record source TU isn't working anymore. I downloaded Version 3.2.1.0 for Studio 2021 plugin and tried to follow the only installation instructions I found on https://community.sdl.com/product-groups/translationproductivity/f/openexchange_applications/7629/installation-assistance-with-record-source-tu but I don't know where to install the plugin since on my C drive I don't get the path suggested in the link (that is, C:\Users\USER NAME\AppData\Roaming\SDL\SDL Trados Studio\12\Plugins\Packages). The path I get is C:\Users\my USER NAME\AppData and then nothing from the above. What is more, I tried to find on my C drive the path "SDL\SDL Trados Studio\12\Plugins\Packages" but no luck. Could you please help me with the installation procedure? 

Many thanks in advance for your help.

Kind regards,

Dimitra