When import package to use it in Jupyter Notebook with function saved in .py file in Python?

I have in Jupyter Lab functions.py file with function which I wrote which use package statsmodels as sm like below:

def my_fk():
  x = sm.Logit()
  ...

Then I import function from my file in Jupyter Notebook like below and I import needed package statsmodels:

import functions as fck
import statsmodels.api as sm

But when I try to use function imported from my file in Jupyter Notebook like below:

fck.my_fk()

I have an error like follow: NameError: name 'sm' is not defined

My question is:
Where should I import package import statsmodels.api as sm needed to run my function, so as to be able to use it in Jupyter Notebook ? In Jupyter Notebook or in .py file where I save my function ?