Help with a project on a secure network

Hello, new to unity and here aswell. I am trying to bring our companies project template from 2018.2 to 2019.1

I had purchased a few assets(vegetation studio pro) that need specific packages that are located in the preview package section.(Burst,Collections,Mathematics,Postprocessing).

My issue though is that we are on a secure network, no line to the outside world. I was able to create a new project in 2019.1 at my house, download the preview packages needed, and then put on my box.

None of the 4 previous mentioned packages come over in the project. Inside the package manager, In project packages, I see them but they all have the same error. getaddrinfo EAI_AGAIN packages.unity.com443.

It states that I seem to be offline, which of course, I am. Is there any way I can get these packages over to my box without having to get online?

 

I have similar issue. May i check any workaround method?

For myself, i literally copy my entire project and install in the non-internet machine. In the non internet machine, i installed the same unity editor, all works well but when i open the project, i encountered some packages have getaddrinfo EAI_AGAIN issue. Why is it so?


Thank you