Django admin wont let me log in with a custom user model

Question

I've done a custom user model and when I try to log in to django admin it says "Please enter the correct email address and password for a staff account. Note that both fields may be case-sensitive.".

I've tried creating a superuser using python manage.py createsuperuser but it returns:

    Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
    self.execute(*args, **cmd_options)
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 61, in execute
    return super().execute(*args, **options)
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "\AppData\Local\Programs\Python\Python37\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 156, in handle
    self.UserModel._default_manager.db_manager(database).create_superuser(**user_data)
TypeError: create_superuser() missing 1 required positional argument: 'username'

I've tried creating a user through CustomUser.objects.create(email=email, ...)

I've tried checking if it is a staff, superuser and active. All of these returned True.

Code

Models.py

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils.translation import gettext_lazy as _


class CustomUser(AbstractUser):
    username = None
    first_name = None
    last_name = None
    email = models.EmailField(_('email address'), blank=False, null=False, unique=True)
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = []
    full_name = models.CharField(_('full name'), max_length=1000, null=True, blank=True)
    user_id = models.CharField(_('session id'), max_length=10000, null=True, blank=True)
    verification_code_time = models.IntegerField(_('time left for session id'), null=True, blank=True)
    verification_code = models.IntegerField(_('verification code'), null=True, blank=True)

    def __str__(self):
        return self.email

Settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',

    'django_user_agents',

    'home',
    'accounts',
    'policies',
]

MIDDLEWARE = [
    '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',

    'django_user_agents.middleware.UserAgentMiddleware',
]
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',
    },
]

AUTH_USER_MODEL = 'accounts.CustomUser'

Any suggestions?