Note: The LTSC (Long Term Servicing Channel) version of Windows 10 is suited for special environments, and environments without Internet certainly are special.
You might know of a simpler or better way, if so feel free to comment. I came up with a solution that works for me and I thought I’d share it. I needed to install Windows 10 LTSC version 2019 in an offline environment (with no internet access) and I also needed to configure language pack settings and configure keyboard layout.
In previous times you could simply install a language pack for the associate language and all was good, now there are additional components that also need to be installed otherwise Windows will attempt to download them from the internet (and notify you via the notification center if it cannot). Sometimes you need to install Windows features that normally need internet access (to install other components), language packs installed today are done in a modular and different format from previous years.