I have success using both of the Path() and Python Sys Path() arguments in Python Init() shown below. Python Path is simply the path to the dll in the virtual environment and you can get the sys path list by launching python in your environment, typing "import sys", then "sys.path" and copy-pasting the output like I have below:
PythonPath = "C:\Users\<userid>\AppData\Local\Programs\Python\Python37\Python37\<Virtual Environment>\Scripts\python37.dll";
PythonSysPathList = {"", "C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37\\<Virtual Environment>\\Scripts\\python37.zip",
"C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37\\DLLs",
"C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37\\lib",
"C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37",
"C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37\\<Virtual Environment>",
"C:\\Users\\<userid>\\AppData\\Local\\Programs\\Python\\Python37\\<Virtual Environment>\\lib\\site-packages"};
Python Init(
Path( PythonPath ),
Python Sys Path( PythonSysPathList )
);
version = Python Get Version();
Show( version );
This is what works for me and it recognizes package imports that I only have installed in my virtual environment. Good luck!