Fail python configuration on ubuntu and python 3.8

hello,

Finally i don’t know how but i think i get success message :

Done. The SNAP-Python interface is located in '/root/.snap/snap-python/snappy/snappy'
When using SNAP from Python, either do: sys.path.append('/root/.snap/snap-python/snappy')
or copy the 'snappy' module into your Python's 'site-packages' directory.

but any time know in python i get this error :

import sys
import os
sys.path.append('/root/.snap/snap-python/snappy')
import snappy
from snappy import ProductIO

error :

    raise IOError("Can't find SNAP distribution directory. Either configure variable 'snap_home' " +
OSError: Can't find SNAP distribution directory. Either configure variable 'snap_home' in file './snappy.ini' or set environment variable 'SNAP_HOME' to an existing SNAP distribution directory.

I need some more step like this :

cd ~/.snap/snap-python/snappy
python3 setup.py install

or :

copy to /usr/local/lib/python3.8/dist-packages/snappy/ the files at …snap\s

any idea ?