$ python manage.py startapp profileapp

# settings.py
# ...
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'bootstrap4',
    'profileapp',
    'accountapp',
]
# ...
# pragmatic\urls.py
# ...
urlpatterns = [
    path('admin/', admin.site.urls),
    path('accounts/', include('accountapp.urls')),
    path('profiles/', include('profileapp.urls')),
]
# profileapp\urls.py
app_name = 'profileapp'
urlpatterns = [
]
# profileapp\models.py
# ...
class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    image = models.ImageField(upload_to='profile/', null=True)
    nickname = models.CharField(max_length=20, unique=True, null=True)
    message = models.CharField(max_length=100, null=True)
# profileapp\forms.py
# ...
class ProfileCreationForm(ModelForm):
    class Meta:
        model = Profile
        fields = ['image', 'nickname', 'message']