python manage.py generateschemaが失敗する

前提・実現したいこと

https://akiyoko.hatenablog.jp/entry/2020/12/08/120230
こちらのブログを参考に、DRFの初期構築をしています。
OpenAPIの情報を出力したいのですが、失敗しています。

発生している問題・エラーメッセージ

bash
1$ python manage.py generateschema --file schema.yml
2usage: manage.py generateschema [-h] [--title TITLE] [--url URL] [--description DESCRIPTION] [--format {openapi,openapi-json}]
3                                [--urlconf URLCONF] [--generator_class GENERATOR_CLASS] [--version] [-v {0,1,2,3}] [--settings SETTINGS]
4                                [--pythonpath PYTHONPATH] [--traceback] [--no-color] [--force-color] [--skip-checks]
5manage.py generateschema: error: unrecognized arguments: --file schema.yml
6
7
8$ python manage.py generateschema
9Traceback (most recent call last):
10  File "manage.py", line 10, in <module>
11    execute_from_command_line(sys.argv)
12  File "/usr/local/lib/python3.8/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
13    utility.execute()
14  File "/usr/local/lib/python3.8/site-packages/django/core/management/__init__.py", line 395, in execute
15    self.fetch_command(subcommand).run_from_argv(self.argv)
16  File "/usr/local/lib/python3.8/site-packages/django/core/management/base.py", line 328, in run_from_argv
17    self.execute(*args, **cmd_options)
18  File "/usr/local/lib/python3.8/site-packages/django/core/management/base.py", line 369, in execute
19    output = self.handle(*args, **options)
20  File "/usr/local/lib/python3.8/site-packages/rest_framework/management/commands/generateschema.py", line 40, in handle
21    schema = generator.get_schema(request=None, public=True)
22  File "/usr/local/lib/python3.8/site-packages/rest_framework/schemas/openapi.py", line 64, in get_schema
23    paths = self.get_paths(None if public else request)
24  File "/usr/local/lib/python3.8/site-packages/rest_framework/schemas/openapi.py", line 47, in get_paths
25    operation = view.schema.get_operation(path, method)
26  File "/usr/local/lib/python3.8/site-packages/rest_framework/schemas/openapi.py", line 95, in get_operation
27    operation['operationId'] = self._get_operation_id(path, method)
28  File "/usr/local/lib/python3.8/site-packages/rest_framework/schemas/openapi.py", line 130, in _get_operation_id
29    name = self.view.get_serializer_class().__name__
30  File "/usr/local/lib/python3.8/site-packages/rest_framework/generics.py", line 122, in get_serializer_class
31    assert self.serializer_class is not None, (
32AssertionError: 'ValidateAuthTokenView' should either include a `serializer_class` attribute, or override the `get_serializer_class()` method.

該当のソースコード

python
1cat manage.py 
2#!/usr/bin/env python
3import os
4import sys
5
6if __name__ == "__main__":
7    os.environ.setdefault("DJANGO_SETTINGS_MODULE", 'settings')
8
9    from django.core.management import execute_from_command_line
10
11    execute_from_command_line(sys.argv)