问mypy和django:错误:没有为"six“安装库存根(或与Python 3.9不兼容)

EN

[mypy]
# The mypy configurations: https://mypy.readthedocs.io/en/latest/config_file.html
python_version = 3.9

check_untyped_defs = True
# disallow_any_explicit = True
disallow_any_generics = True
disallow_untyped_calls = True
disallow_untyped_decorators = True
ignore_errors = False
ignore_missing_imports = True
implicit_reexport = False
strict_optional = True
strict_equality = True
no_implicit_optional = True
warn_unused_ignores = True
warn_redundant_casts = True
warn_unused_configs = True
warn_unreachable = True
warn_no_return = True
mypy_path = /home/user/app/backend_django/src

plugins =
  mypy_django_plugin.main,
  mypy_drf_plugin.main

[mypy.plugins.django-stubs]
django_settings_module = project.settings

settings.py:21: error: Library stubs not installed for "six" (or incompatible with Python 3.9)