Django custom user creation not displaying custom fields in admin site

I'm trying to create a cutom user in my Django with custom fields like first_name, last_name, date_of_birth, gender, email, etc. So for this I have overridden AbstractBaseUser

for my custom user UserCreationForm

to create a new user and UserChangeForm

change the values ​​of the user fields.

Models.py

    class AppUserManager(BaseUserManager):
        """
        Manager for class AppUser
        """

        def _create_user(self, username, password, first_name, last_name,
                         date_of_birth, email, gender, is_staff, is_superuser,
                         **extra_fields):
            """
            Creates and saves a User with the given username, email and password.
            """
            now = timezone.now()
            if not username:
                raise ValueError('The given username must be set')
            email = self.normalize_email(email)
            user = self.model(username=username,
                              first_name=first_name, last_name=last_name,
                              date_of_birth=date_of_birth, email=email, gender=gender,
                              is_staff=is_staff, is_active=True,
                              is_superuser=is_superuser, last_login=now,
                              date_joined=now, **extra_fields)
            user.set_password(password)
            user.save(using=self._db)
            return user

        def create_user(self, username, password, first_name, last_name, date_of_birth, email, gender, **extra_fields):
            return self._create_user(username, password, first_name, last_name,
                                     date_of_birth, email, gender, False, False,
                                     **extra_fields)

        def create_superuser(self, username, password, first_name, last_name, date_of_birth, email, gender, **extra_fields):
            return self._create_user(username, password, first_name, last_name,
                                     date_of_birth, email, gender, True, True,
                                     **extra_fields)


    class AppUser(AbstractBaseUser, PermissionsMixin):
        """
        User for Application
        """

        username = models.CharField(verbose_name='username', max_length=30, unique=True,
                                    help_text='Required. 30 characters or fewer. Letters, digits and '
                                              '@/./+/-/_ only.',
                                    validators=[
                                        validators.RegexValidator(r'^[\w.@+-]+$', 'Enter a valid username.', 'invalid')
                                    ])

        first_name = models.CharField(verbose_name='first name', max_length=30)

        last_name = models.CharField(verbose_name='last name', max_length=30)

        date_of_birth = models.DateField(verbose_name='birth date')

        email = models.EmailField(verbose_name='email address', unique=True)

        GENDER_CHOICES = (
            ('m', 'Male'),
            ('f', 'Female'),
        )
        gender = models.CharField(verbose_name='gender', max_length=1, choices=GENDER_CHOICES)

        is_staff = models.BooleanField(verbose_name='staff status', default=False,
                                       help_text='Designates whether the user can log into this admin '
                                                 'site.')
        is_active = models.BooleanField(verbose_name='active status', default=True,
                                        help_text='Designates whether this user should be treated as '
                                                  'active. Un select this instead of deleting accounts.')
        date_joined = models.DateTimeField(verbose_name='date joined', default=timezone.now)

        objects = AppUserManager()

        USERNAME_FIELD = 'username'
        REQUIRED_FIELDS = ['first_name', 'last_name', 'date_of_birth', 'email', 'gender']

        class Meta:
            verbose_name = 'user'
            verbose_name_plural = 'users'
            db_table = 'app_users'

        def get_full_name(self):
            """
            Returns the first_name plus the last_name, with a space in between.
            """
            full_name = '%s %s' % (self.first_name, self.last_name)
            return full_name.strip()

        def get_short_name(self):
            """Returns the short name for the user."""
            return self.first_name

        def email_user(self, subject, message, from_email=None, **kwargs):
            """
            Sends an email to this User.
            """
            send_mail(subject, message, from_email, [self.email], **kwargs)

      

        
        
        
      

    

admin.py

    class CustomUserCreationForm(UserCreationForm):
        """
        A form for creating new users. Includes all the required fields, plus a repeated password.
        """
        password1 = forms.CharField(label='Password', widget=forms.PasswordInput)
        password2 = forms.CharField(label='Password Confirmation', widget=forms.PasswordInput)
        first_name = forms.CharField(label='First Name')  # Custom Required Field. and other fields should go same way 

        class Meta(UserCreationForm.Meta):
            model = AppUser
            fields = ('username', 'first_name', 'last_name', 'date_of_birth', 'email', 'gender')

        def clean_username(self):
            username = self.cleaned_data["username"]

            try:
                AppUser.objects.get(username=username)
            except AppUser.DoesNotExist:
                return username
            raise forms.ValidationError(self.error_messages['duplicate_username'])

        def clean_password2(self):
            # Check that the two password entries match
            password1 = self.cleaned_data.get("password1")
            password2 = self.cleaned_data.get("password2")

            if password1 and password2 and password1 != password2:
                raise forms.ValidationError("Passwords do not match.")
            return password2

        def save(self, commit=True):
            # Save the provided password in hashed format
            user = super(UserCreationForm, self).save(commit=False)
            user.set_password(self.cleaned_data["password1"])
            if commit:
                user.save()
            return user


    class CustomUserChangeForm(UserChangeForm):
        password = ReadOnlyPasswordHashField(label="password",
                                             help_text="""Raw passwords are not stored, so there is no way to see this
                                             user password, but you can change the password using <a href=\"password/\">
                                             this form</a>.""")

        class Meta(UserChangeForm.Meta):
            model = AppUser
            fields = (
                'username', 'first_name', 'last_name', 'date_of_birth', 'email', 'gender',
                'password', 'is_active', 'is_staff', 'is_superuser', 'user_permissions'
            )

        def clean_password(self):
            # Regardless of what the user provides, return the initial value.
            # This is done here, rather than on the field, because the
            # field does not have access to the initial value
            return self.initial["password"]


    class AppUserAdmin(UserAdmin):
        """

        """
        form = CustomUserChangeForm
        add_form = CustomUserCreationForm

        list_display = ('username', 'first_name', 'last_name', 'email',)
        list_filter = ('is_superuser',)

        fieldsets = (
            (None, {'fields': (
                'username', 'first_name', 'last_name', 'date_of_birth', 'email', 'gender',
            )}),
            ('Permissions', {'fields': (
                'is_active', 'is_superuser', 'is_staff',
            )}),
        )

        search_fields = ('username', 'email', 'first_name', 'last_name',)
        ordering = ('username', 'email',)


    admin.site.register(AppUser, AppUserAdmin)

      

        
        
        
      

    

I created a superuser from the command line. But in the form for adding a user, only the fields "Username", "Password" and "Confirm password" are displayed.

So how can I get the fields to create a custom form displaying the required fields?

After submitting it gives me an error:

Exception Type: IntegrityError at /admin/users/appuser/add/
Exception Value: Column 'date_of_birth' cannot be null