USERNAME_FIELD = 'email'
REQUIRED_FIELDS = ['username']

User._meta.get_field('email')._unique = True

USERNAME_FIELD = 'email'

def registration(request):
    if request.method == 'POST':
        user = User()
        company = Company()
        form = RegistrationForm(request.POST)
        if form.is_valid():
            user.first_name = form.cleaned_data['first_name']
            user.last_name = form.cleaned_data['last_name']
            user.email = form.cleaned_data['email']
            user.username = form.cleaned_data['email']
            user.password = form.cleaned_data['password']
            user.role = 'boss'
            company.name = user.last_name + " " + user.first_name
            company.creator = user.first_name + " " + user.last_name
            company.save()
            user.company = company
            user.save()
            return redirect('/good_luck/')
    else:
        form = RegistrationForm()

    return render(request, 'registration.html', {'form': form})

class RegistrationForm(Form):
    first_name = CharField(label='Имя', max_length=130, required=True)
    last_name = CharField(label='Фамилия', max_length=130, required=True)
    email = EmailField(label='Почта', max_length='130', required=True)
    password = CharField(label='Пароль', required=True)

class EmailAuthBackend(object):

    @staticmethod
    def authenticate(email=None, password=None):
        try:
            user = User.objects.get(email=email)
        except User.DoesNotExist:
            return None

        if not user.check_password(password):
            return None

        return user

    @staticmethod
    def get_user(user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None

AUTHENTICATION_BACKENDS = [
    'путь_к_модулю.EmailAuthBackend'
]

from django.contrib.auth import login, authenticate
from django.http.response import HttpResponse

user = authenticate(email=email,password=password)

if user is None:
    # Пользователь с таким имейлом и паролем не найден.

# Если всё хорошо, логиним пользователя
login(request, user)
return HttpResponse(status=200)