$ django-admin startproject backend

$ python manage.py startapp blog
$ python manage.py migrate
$ python manage.py runserver

# backend/setting.py

INSTALLED_APPS = [
        'django.contrib.admin',
        'django.contrib.auth',
        'django.contrib.contenttypes',
        'django.contrib.sessions',
        'django.contrib.messages',
        'django.contrib.staticfiles',
        'blog' # add our app here 
      ]

# backend/blog/models.py

from django.conf import settings
from django.db import models
from django.utils import timezone 

# Create your models here.

class Post(models.Model):
    author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    title = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(default = timezone.now)
    published_date = models.DateTimeField(blank = True, null = True)

    def publish(self):
        self.published_date = timezone.now()
        self.save()
    
    def __str__(self):
        return self.title

$ python manage.py makemigrations blog
$ python manage.py migrate blog