Is there any guide how to grab .dll library files for Unity3d to put them into Plugin folder?

Working with Data Drivers
,
1

I found this repo - GitHub - Julian23517/Unity-mongo-csharp-driver-dlls
but each time I try to grab similar dll files from nuget I got errors.
I want to be able to update my database to newest versions in future inside Unity3d.

2

Needed just to download .dlls for .Net supported by Uniyt3d and all is working.