There are designed to be downloaded automatically by Install-Voukoder
You may use the zip for manual installation, unarchive into %APPDATA%\VEGAS\Render Templates\voukoder (create the voukoder folder if it does not exist yet)
If you make use of older versions of VEGAS Pro
Back when it was owned by Sony, folder paths might have been different, so they may not even show up when in that folder, if not save a custom preset with any render template and use Everything to search where the .sft2 preset is located