LTSC means you are using volume licensing. This version is different than regular Office products. In order to get the LTSC version follow the steps documented here. After you've downloaded the ODT tool, set up the config file and downloaded the actual installation then you can install it.
Note that if you're testing this stuff then most likely your company already has the config file they use. Most likely they've already downloaded the installation as well, otherwise they cannot install Office. I would ask for the config file first.