Не получается добавить SuccessMessageMixin

from django.contrib.messages.views import SuccessMessageMixin
from bootstrap_modal_forms.mixins import PassRequestMixin
from django.views.generic.edit import CreateView
from .models import company
from .forms import companyForm
class CompanyCreateView( SuccessMessageMixin,PassRequestMixin
                         ,CreateView):
    template_name = 'fvs/CreateModal.html'
    form_class = companyForm
    success_url = '/Company/'
    success_message = "Successfully"

INSTALLED_APPS = [
    # Add your apps here to enable them
    'fvs',
    'FVSapp',
    'django_tables2',
    'bootstrap_modal_forms',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]
MIDDLEWARE_CLASSES = [
    'django.middleware.common.CommonMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.security.SecurityMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]
 
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.contrib.messages.context_processors.messages',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
            ],
        },
    },
]

INSTALLED_APPS = [
    # Add your apps here to enable them    
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'fvs',
    'FVSapp',
    'django_tables2',
    'bootstrap_modal_forms',
]