I can't start the database after running the command: excalibur initdb

I get this error:

~$ excalibur initdb
Creating new Excalibur configuration file in: /home/localhost/excalibur/excalibur.cfg
Traceback (most recent call last):
File "/home/localhost/.local/bin/excalibur", line 5, in
from excalibur.cli import cli
File "/home/localhost/.local/lib/python3.6/site-packages/excalibur/cli.py", line 12, in
from .www.app import create_app
File "/home/localhost/.local/lib/python3.6/site-packages/excalibur/www/app.py", line 7, in
from .views import views
File "/home/localhost/.local/lib/python3.6/site-packages/excalibur/www/views.py", line 10, in
from werkzeug import secure_filename
ImportError: cannot import name 'secure_filename'

It seems that the library mentioned is already installed.

~$ pip3 install werkzeug
Requirement already satisfied: werkzeug in ./.local/lib/python3.6/site-packages (1.0.0)
WARNING: You are using pip version 19.2.3, however version 20.0.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

Any tip?