How to serve static files with django-rest framework?

Question

I am new to Django development and I want to deploy my project on Azure WebApp service. When I switch to DEBUG = False, I get this error :

The resource from “http://127.0.0.1:8000/static/css/index.css” was blocked due to MIME type (“text/html”) mismatch (X-Content-Type-Options: nosniff).

Yet, I followed the steps described in this post : ALLOWED_HOSTS and Django I understood Django does not serve the static files by itself, that's why I installed WhiteNoise and put in the Middleware. (As shown in the post above.) Thus I don't understand why I have this error.

Here my settings.py :

"""
Django settings for WebApp project.

Generated by 'django-admin startproject' using Django 3.1.4.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""

from pathlib import Path
import os

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent

# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'my_hidden_secret_key'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = False

ALLOWED_HOSTS = ['localhost', '127.0.0.1']

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'django.contrib.sites',
    'api.apps.ApiConfig',
    'rest_framework',
    'rest_framework.authtoken',
    'rest_auth',
    'allauth',
    'allauth.account',
    'allauth.socialaccount',
    'rest_auth.registration',
    'corsheaders',
    'frontend.apps.FrontendConfig',
    'users'
]

MIDDLEWARE = [
    'corsheaders.middleware.CorsMiddleware',
    'whitenoise.middleware.WhiteNoiseMiddleware',
    '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',
]

ROOT_URLCONF = 'WebApp.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'WebApp.wsgi.application'

# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

LANGUAGE_CODE = 'fr'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'

STATIC_ROOT = os.path.join(BASE_DIR, 'static')

# Base url to serve media files
MEDIA_URL = '/media/'

# Path where media is stored
MEDIA_ROOT = os.path.join(BASE_DIR, 'media/')

AUTH_USER_MODEL = 'users.CustomUser'

CORS_ALLOWED_ORIGINS = [
    'http://localhost:3000'
]

EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'

AUTHENTICATION_BACKENDS = (
    "django.contrib.auth.backends.ModelBackend",
    "allauth.account.auth_backends.AuthenticationBackend",
)

SITE_ID = 1
ACCOUNT_EMAIL_REQUIRED = True
ACCOUNT_USERNAME_REQUIRED = False
ACCOUNT_SESSION_REMEMBER = True
ACCOUNT_AUTHENTICATION_METHOD = 'email'
ACCOUNT_UNIQUE_EMAIL = True

REST_FRAMEWORK = {
    'DATETIME_FORMAT': "%m/%d/%Y %I:%M%P",
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework.authentication.TokenAuthentication',
    ],
}

Thanks for your help !