How to insert data into User model without using django forms?

I am working on a django project where I can't use django forms, and I'm facing a lot of problem when trying to access the abstract user objects,can anyone please tell me how to access these objects?

and here is my models.py file where I created a custom user so I can register and login using email.

models.py

class CustomUser(AbstractUser):
    username = None
    email = models.EmailField(_("email address"), unique=True)

    USERNAME_FIELD = "email"
    REQUIRED_FIELDS = []

    objects = CustomUserManager()

    def __str__(self):
        return self.email

class Shahadati_user(models.Model):
    user = models.OneToOneField(CustomUser,on_delete=models.CASCADE)
    user_nID=models.PositiveIntegerField(primary_key=True)

    def __str__(self):
        return self.user.email

below the views.py file, and the problem for me that I don't know how to access the first_name, last_name password, etc. objects that are in the abstract user model.

views.py

def user_reg(request):
    
    registered = False

    if request.method == "POST":
        first_name = request.POST.get('FirstName')
        last_name = request.POST.get('LastName')
        nID = request.POST.get('nID')
        Email = request.POST.get('em')
        password = request.POST.get('psw')

        ######### the following code case the problem ########
        if password == request.POST.get('pswValidation'):
            hashed_password=make_password(password,None)
            user = Shahadati_user (first_name=first_name,
                                              last_name=last_name,
                                              user_national_id=nID,
                                              email=Email,
                                              password=hashed_password,
                                            )
            
            user.save()

        else:
            raise ValidationError(_("Passwords are not the same !"))
    return render(request, 'Register.html', {'regitered': registered})

source https://stackoverflow.com/questions/75761289/how-to-insert-data-into-user-model-without-using-django-forms