Returing result of synchonous function inside async function in python

Question

I'm newbie in the world of python and have been trying to solve the following for last 3 days on my own. I read many articles online none of them address my problem or I seem to been missing something so I decided to post my question here.

Purpose:- I'm trying to connect realtime data from my broker to a charting library via 'socketio python' websocket which I host locally and runs on an ASGI server. Broker has provided following two sync functions which I've wrapped inside an async fuction SubAdd but couldn't get an output from

@sio.event
async def SubAdd(sid,data):      #event that handles subscribe requests from  library for realtime data

   def socket(access_token): #This funtion gets the data from broker
    data_type = "symbolData"
    symbol =["NSE:NIFTYBANK-INDEX"]
    fs = ws.FyersSocket(access_token=access_token,run_background=False,log_path="/home/log/")
    fs.websocket_data = custom_message
    fs.subscribe(symbol=symbol,data_type=data_type)
    fs.keep_running()

   def custom_message(msg):# Function that returns fetched data
       print (f"Custom:{msg}")

   socket(access_token)

A thing that confused me the most is at the line 4 of socket i.e.fs.websocket_data = custom_message. Normally, if we write A=B then left side of assignment operator gets assigned the value of right side i.e. A is getting value from B But something else is happening here I dont know what?

Thing I've tried:

1. making both socket and custome_message an async fuction and then yielding sio.emit from inside async custom_message

2. making both socket and custome_message an async fuction and then awiting/yielding to the append msg to another list and then using async for on that list and then await sio.emit

Both of above gave an error RuntimeWarning: coroutine 'SubAdd.<locals>.socket' was never awaited which clearly means I'm heading in the wrong direction.

So my question is how do I wrap these two sync functions inside an async function and get an awaitable output from custom_message. If you could directly answer the question its well and good but even if you point me to the a link to a resource or even a keyword to search, which you think would answer my question is greatly appreciated. Thank you.