점프투 장고에서 02-6 챕터 96페이지까지 진행했는데

Internal Server Error: /pybo/answer/create/1/
Traceback (most recent call last):
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\sqlite3\base.py", line 413, in execute      
    return Database.Cursor.execute(self, query, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sqlite3.IntegrityError: NOT NULL constraint failed: pybo_answer.content

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\core\handlers\base.py", line 179, in _get_response      
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\djangoworkspace\django1\pybo\views.py", line 28, in answer_create
    question.answer_set.create(content=request.POST.get('content'), create_date=timezone.now())
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\fields\related_descriptors.py", line 677, in create
    return super(RelatedManager, self.db_manager(db)).create(**kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\manager.py", line 85, in manager_method       
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\query.py", line 447, in create
    obj.save(force_insert=True, using=self.db)
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\base.py", line 753, in save
    self.save_base(using=using, force_insert=force_insert,
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\base.py", line 790, in save_base
    updated = self._save_table(
              ^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\base.py", line 895, in _save_table
    results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\base.py", line 933, in _do_insert
    return manager._insert(
           ^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\manager.py", line 85, in manager_method       
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\query.py", line 1254, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\sql\compiler.py", line 1397, in execute_sql   
    cursor.execute(sql, params)
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 98, in execute
    return super().execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 79, in _execute
    with self.db.wrap_database_errors:
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\lecha\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\backends\sqlite3\base.py", line 413, in execute      
    return Database.Cursor.execute(self, query, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
django.db.utils.IntegrityError: NOT NULL constraint failed: pybo_answer.content

이라고 에러가 뜹니다. 어떻게 해야 할까요?
참고로 코드는
config/urls.py

from django.contrib import admin
from django.urls import path, include
from pybo import views

urlpatterns = [
    path('admin/', admin.site.urls),
    path('pybo/', include('pybo.urls')),
]

pybo/urls.py

from django.urls import path
from . import views

app_name = 'pybo'

urlpatterns = [
    path('', views.index, name='index'),
    path('<int:question_id>/', views.detail, name='detail'),
    path('answer/create/<int:question_id>/', views.answer_create, name='answer_create'),
]

views.py

from django.shortcuts import render, get_object_or_404, redirect
from .models import Question
from django.utils import timezone

# Create your views here.

def index(request):
    """
    pybo 목록 출력
    """
    question_list = Question.objects.order_by('-create_date')
    context = {'question_list': question_list}
    return render(request, 'pybo/question_list.html', context)

def detail(request, question_id):
    """
    pybo 내용 출력
    """
    question = get_object_or_404(Question, pk=question_id)
    context = {'question': question}
    return render(request, 'pybo/question_detail.html', context)

def answer_create(request, question_id):
    """
    pybo 답변 등록
    """
    question = get_object_or_404(Question, pk=question_id)
    question.answer_set.create(content=request.POST.get('content'), create_date=timezone.now())
    return redirect('pybo:detail', question_id=question.id)

models.py

from django.db import models

class Question(models.Model):
    subject = models.CharField(max_length=200)
    content = models.TextField()
    create_date = models.DateTimeField()
    def __str__(self):
        return self.subject

class Answer(models.Model):
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    content = models.TextField()
    create_date = models.DateTimeField()

admin.py

from django.contrib import admin
from .models import Question

class QuestionAdmin(admin.ModelAdmin):
    search_fields = ['subject']

admin.site.register(Question, QuestionAdmin)

settings.py

(생략)
INSTALLED_APPS = [
    'pybo.apps.PyboConfig',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]
(생략)
LANGUAGE_CODE = 'ko-kr'

TIME_ZONE = 'Asia/Seoul'
(생략)

apps.py

from django.apps import AppConfig

class PyboConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'pybo'

question_list.html

{% if question_list %}
    <ul>
    {% for question in question_list %}
        <li><a href="{% url 'pybo:detail' question.id %}">{{ question.subject }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>질문이 없습니다.</p>
{% endif %}

question_detail.html

<h1>{{ question.subject }}</h1>

<div>
    {{ question.content }}
</div>

<h5>{{ question.answer_set.count }}개의 답변이 있습니다.</h5>
<div>
    <ul>
    {% for answer in qustion.answer_set.all %}
        <li>{{ answer.content }}</li>
    {% endfor %}
    </ul>
</div>

<form action="{% url 'pybo:answer_create' question.id %}" method="post">
{% csrf_token %}
<textarea name="contet" id="content" rows=15></textarea>
<input type="submit" value="답변 등록">
</form>

입니다.