How to fix NOT NULL constraint failed: create_create.category_id error?

Question

Django

How to fix NOT NULL constraint failed: create_create.category_id error.

0001_initial.py :

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

    initial = True

    dependencies = [
    
    ]

    operations = [
        migrations.CreateModel(
            name='Create',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('name', models.CharField(db_index=True, max_length=200)),
                ('slug', models.SlugField(max_length=200)),
                ('image', models.ImageField(blank=True, upload_to='products/%Y/%m/%d')),
                ('description', models.TextField(blank=True)),
                ('price', models.DecimalField(decimal_places=2, max_digits=10)),
                ('available', models.BooleanField(default=True)),
                ('created', models.DateTimeField(auto_now_add=True)),
                ('updated', models.DateTimeField(auto_now=True)),
            ],
            options={
                'ordering': ('name',),
                'index_together': {('id', 'slug')},
            },
        ),
    ]

models.py:

from django.db import models
from django.conf import settings
from django.urls import reverse
from django.template.defaultfilters import slugify


class Create(models.Model):
    name = models.CharField(max_length=200, db_index=True)
    slug = models.SlugField(max_length=200, db_index=True)
    image = models.ImageField(upload_to='products/%Y/%m/%d', blank=True)
    description = models.TextField(blank=True)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    available = models.BooleanField(default=True)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ('name',)
        index_together = (('id', 'slug'),)

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
        super(Create, self).save(*args, **kwargs)

    def __str__(self):^M       
         return self.name

    def get_absolute_url(self):
        return reverse('catalog:product_detail', args=[self.id, self.slug])