Following Hironsan review, did some change.

app/app/settings.py

@@ -88,7 +88,7 @@ ROOT_URLCONF = 'app.urls'
 TEMPLATES = [
     {
         'BACKEND': 'django.template.backends.django.DjangoTemplates',
-        'DIRS': [path.join(BASE_DIR, 'server/templates'),path.join(BASE_DIR, 'authentification/templates')],
+        'DIRS': [path.join(BASE_DIR, 'server/templates'), path.join(BASE_DIR, 'authentification/templates')],
         'APP_DIRS': True,
         'OPTIONS': {
             'context_processors': [

app/authentification/forms.py

@@ -1,7 +1,8 @@
 from django import forms
 from django.contrib.auth.forms import UserCreationForm
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
 
+User = get_user_model()
 
 class SignupForm(UserCreationForm):
     email = forms.EmailField(max_length=200, help_text='Required')

app/authentification/utils.py

@@ -4,7 +4,9 @@ from django.contrib.auth import login
 from django.utils.encoding import force_text
 from django.utils.http import urlsafe_base64_decode
 from .tokens import account_activation_token
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
+
+User = get_user_model()
 
 
 def activate(request, uidb64, token):

docker-compose.yml

@@ -12,7 +12,7 @@ services:
       ADMIN_PASSWORD: "password"
       ADMIN_EMAIL: "admin@example.com"
       DATABASE_URL: "postgres://doccano:doccano@postgres:5432/doccano?sslmode=disable"
-      ALLOW_SIGNUP: "True" 
+      ALLOW_SIGNUP: "False" 
     ports:
       - 8000:8000