ModuleNotFoundError: No module named 'lascar.tools'

Dear all,
To use lascar module, in my jupyter notebook, I typed

git clone https://github.com/Ledger-Donjon/lascar.git
cd lascar
  Then I found that the execution of the following line
python3 setup.py develop

would take too much time; thus I type this line in my command line terminal.
Then I restart the kernel; I execute the following lines in jupyter notebook,

from lascar import *
from lascar.tools.aes import sbox, inv_sbox

I got an error message as:
ModuleNotFoundError: No module named ‘lascar.tools’

Why?

If you remove the from lascar.tools.aes import sbox, inv_sbox line, does the command succeed?

Alex