Can I control Metahuman face Expression using python script?

You may be able to write something that leverages the Python bindings for Live Link: Search — Unreal Python 4.27 (Experimental) documentation

Live Link is the API that things like the iPhone or iClone use to provide animations for the body and face of characters. You’d need to find or implement something to drive the API from Python and you’d need to adjust the facial animation blueprints of the MH so they have a reference pose that can translate the inputs you’re providing into the appropriate animation parameters.