Migrate error in example app

[tonimore]

I've tried to install example app, step by step, but got error on migrate:

Requirements installed successfully:

(.venv) Mabook:example usr001$ pip install -r requirements.txt
Processing /Users/usr001/Syno/code/phdb/django-bootstrap4
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
    Preparing wheel metadata ... done
Collecting django>=2.2
  Using cached Django-4.0.1-py3-none-any.whl (8.0 MB)
Collecting asgiref<4,>=3.4.1
  Using cached asgiref-3.4.1-py3-none-any.whl (25 kB)
Collecting beautifulsoup4>=4.8.0
  Using cached beautifulsoup4-4.10.0-py3-none-any.whl (97 kB)
Collecting soupsieve>1.2
  Using cached soupsieve-2.3.1-py3-none-any.whl (37 kB)
Collecting sqlparse>=0.2.2
  Using cached sqlparse-0.4.2-py3-none-any.whl (42 kB)
Building wheels for collected packages: django-bootstrap4
  Building wheel for django-bootstrap4 (PEP 517) ... done
  Created wheel for django-bootstrap4: filename=django_bootstrap4-21.2-py3-none-any.whl size=24550 sha256=9a20e97e670b0ac0678b7b5ae34980a8cc393514e4cc01ce10e97cd7acbe31b7
  Stored in directory: /Users/usr001/Library/Caches/pip/wheels/6f/e0/50/6370e32c74389711a7e7adb336a035f540e5543fefa87178a4
Successfully built django-bootstrap4
Installing collected packages: sqlparse, soupsieve, asgiref, django, beautifulsoup4, django-bootstrap4
Successfully installed asgiref-3.4.1 beautifulsoup4-4.10.0 django-4.0.1 django-bootstrap4-21.2 soupsieve-2.3.1 sqlparse-0.4.2
WARNING: You are using pip version 20.3.3; however, version 21.3.1 is available.
You should consider upgrading via the '/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/bin/python3 -m pip install --upgrade pip' command.

Next step finished with error:

(.venv) Mabook:example usr001$ python manage.py migrate
Traceback (most recent call last):
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/example/manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/__init__.py", line 425, in execute_from_command_line
    utility.execute()
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/__init__.py", line 419, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/base.py", line 373, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/base.py", line 417, in execute
    output = self.handle(*args, **options)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/base.py", line 90, in wrapped
    res = handle_func(*args, **kwargs)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/commands/migrate.py", line 75, in handle
    self.check(databases=[database])
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/management/base.py", line 438, in check
    all_issues = checks.run_checks(
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/checks/registry.py", line 77, in run_checks
    new_errors = check(app_configs=app_configs, databases=databases)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/checks/urls.py", line 13, in check_url_config
    return check_resolver(resolver)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/core/checks/urls.py", line 23, in check_resolver
    return check_method()
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/urls/resolvers.py", line 446, in check
    for pattern in self.url_patterns:
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/utils/functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/urls/resolvers.py", line 632, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/utils/functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/urls/resolvers.py", line 625, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/local/Cellar/python@3.9/3.9.1_6/Frameworks/Python.framework/Versions/3.9/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 790, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "/Users/usr001/Syno/code/phdb/django-bootstrap4/example/urls.py", line 1, in <module>
    from django.conf.urls import url
ImportError: cannot import name 'url' from 'django.conf.urls' (/Users/usr001/Syno/code/phdb/django-bootstrap4/.venv/lib/python3.9/site-packages/django/conf/urls/__init__.py)