Bloomberg python API (blpapi) installation error

Question

I would like to use Bloomberg desktop API for Python. To do this I have to install package blpapi.

My Bloomberg terminal PC environment :

1. WIN10(64bit)
2. Ananconda 4.13.0 and Python 3.9.12
3. No internet environment

Due to no internet environment, I could not use pip install option.

Instead I received installation files and tried to install python setup.py install

However I enconter error and belows. How to handle it?

Traceback (most recent call last):
  File "C:\Users\bok\Downloads\blpapi-3.18.3\setup.py", line 49, in <module>
    assert blpapiRoot or (blpapiIncludesVar and blpapiLibVar), (
AssertionError: BLPAPI_ROOT (or BLPAPI_INCDIR/BLPAPI_LIBDIR) environment variable isn't defined