AttributeError: 'AnonymousUser' object has no attribute '_meta' error using a custom registration form

Good Day! I'm trying to make the user of my website register and login with only the email, but I'm getting this error:

AttributeError: 'AnonymousUser' object has no attribute '_meta'

Even if I've this error the account is saved in the database, but I can't login (I've the same error for both registration and login). This is my code:

views.py

def register_view(request, *args, **kwargs):
    user =request.user
    if user.is_authenticated:
        return HttpResponse(f"You are already authenticated as {user.email}.")
    context = {}

    if request.method == 'POST':
        form = RegistrationForm(request.POST)
        if form.is_valid():
            form.save()
            email = form.cleaned_data.get('email').lower()
            raw_password = form.cleaned_data.get('password1')
            account = authenticate(email=email, password=raw_password)
            login(request, account, backend= 'django.contrib.auth.backends.AllowAllUsersModelBackend')
            destination = get_redirect_if_exists(request)
            if destination:
                return redirect(destination)
            return redirect("home") 
        else: 
            context['registration_form'] = form

    return render(request, 'registration/register.html', context)

def logout_view(request):
    logout(request)
    return redirect("home")

def login_view(request, *args, **kwargs):

    context = {}

    user = request.user
    if user.is_authenticated:
        return redirect("home")
    
    if request.POST:
        form = AccountAuthenticationForm(request.POST)
        if form.is_valid():
            email = request.POST['email']
            password = request.POST['password']
            user =authenticate(email=email, password=password)
        if user:
            login(request, user, backend= 'django.contrib.auth.backends.AllowAllUsersModelBackend')
            destination = get_redirect_if_exists(request)
            if destination:
                return redirect(destination)
            return redirect("home") 
        else:
            context['login_form'] = form
    return render(request, "registration/login.html", context)


def get_redirect_if_exist(request):
    redirect = None
    if request.GET:
        if request.GET.get("next"):
            redirect = str(request.GET.get("next"))
    return redirect

Also this is not the first error I'm getting, so I was wondering it this is actually a good code to do what I want or should I restart trying another way. Thank you

EDIT: I added the traceback of the error and also my admin.py and setting.py file since it seems that issue may be in this part (but I still have no idea how to solve it. Thank you again!

Environment:

Request Method: POST
Request URL: http://localhost:8000/main_page/register/

Django Version: 3.2.3
Python Version: 3.8.5
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'main_page']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']

Traceback (most recent call last):
  File "C:\Users\Programs\Python\Python38-32\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\Programs\Python\Python38-32\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "D:\website\main_page\views.py", line 32, in register_view
    login(request, account, backend= 'django.contrib.auth.backends.AllowAllUsersModelBackend')
  File "C:\Users\Programs\Python\Python38-32\lib\site-packages\django\contrib\auth\__init__.py", line 129, in login
    request.session[SESSION_KEY] = user._meta.pk.value_to_string(user)
  File "C:\Users\Programs\Python\Python38-32\lib\site-packages\django\utils\functional.py", line 247, in inner
    return func(self._wrapped, *args)

Exception Type: AttributeError at /main_page/register/
Exception Value: 'AnonymousUser' object has no attribute '_meta'

admin.py

class AccountAdmin(UserAdmin):
    list_display = ('email', 'date_joined', 'last_login', 'is_admin', 'is_staff')
    ordering = ('email',)
    search_field = ('email')
    #readonly_fields = ('id', 'data_joined', 'last_login')

    filter_horizontal = ()
    list_filter = ()
    fieldsets = ()

admin.site.register(Account, AccountAdmin)

setting.py

ALLOWED_HOSTS = []

AUTH_USER_MODELS = "main_page.Account"
AUTHENTICATION_BACKENDS = (
    'django.contrib.auth.backends.AllowAllUsersModelBackend',
    'main_page.backends.CaseInsensitiveModelBackend'
    )

forms.py

class RegistrationForm(UserCreationForm):

    email = forms.EmailField(max_length=255, help_text="Required. Add a valid email adress.")

    class Meta:
        model = Account
        fields = ('email', 'password1', 'password2')

    def clean_email(self):
        email = self.cleaned_data['email'].lower()
        try:
            account = Account.objects.get(email=email)
        except Exception as e:
            return email
        raise forms.ValidationError(f"Email {email} is alaready in use.") 

class AccountAuthenticationForm(forms.ModelForm):

    password = forms.CharField(label=("password"), widget=forms.PasswordInput)

    class Meta:
        model = Account
        fields = ('email', 'password')

    def clean(self):
        if self.is_valid():
            email = self.cleaned_data['email']
            password = self.cleaned_data['password']
            if not authenticate(email=email, password=password):
                raise forms.ValidationError("Invalid Login")