The DLLs are taken directly from the Unity installation of each Editor which you can find at \Program Files\Unity\Hub\Editor\YOUR_UNITY_VERSION\Editor\Data\MonoBleedingEdge\lib\mono\4.8-api in case ...
This repository contains a Unity 3D project created by following the official Roll-a-Ball tutorial from Unity Learn (version 6.0). This project was built step-by-step by following the tutorial ...