Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
In very simplified terms, the Citrix window you are seeing, is the video feed of the computer that sits in the main contractor's office.
There is no connection between that computer and yours, you are merely seeing the video feed of that main contractor's machine. When you operate your mouse and keyboard in the Citrix window, you are remote controlling the machine in your main contractor's office.
As such, treat them as two physically separate machines. They do not share the same software, memory, hard-disk etc, and you generally cannot cut/paste stuff from one to the other.
So the software will be separate and you need to contact the main con to add whatever you need to the Citrix environment.