I’ve faced the same problem, followed these instructions and it worked for me:

1. python -m pip install --upgrade pip (to upgrade pip)
2. pip3 install djangorestframework
3. Added rest_framework as first app:

   INSTALLED_APPS = [
       'rest_framework',
       'django.contrib.admin',
       'django.contrib.auth',
       'django.contrib.contenttypes',
       'django.contrib.sessions',
       'django.contrib.messages',
       'django.contrib.staticfiles',
       #apps
       'apps.endpoints',
   ]