Some days ago I need to install additional language on windows server 2019. I will share with you how to do it.
Firts, you need to download ISO language pack for Windows Server 2019 and mount this image by double clicking and then it will show as a DVD drive in “This PC”.
Next, need to start lpksetup.exe. Choose option 1: Install display languages.
Search for language you want to install.
Accept license.
Wait some time and then language will be available to set.