wagtail_bakerydemo/bakerydemo/base/management/commands/reset_admin_password.py

from django.conf import settings
from django.contrib.auth.models import User
from django.core.management.base import BaseCommand, CommandError


class Command(BaseCommand):
    def handle(self, **options):
        try:
            admin_user = User.objects.get(username="admin")
        except User.DoesNotExist:
            raise CommandError("Cannot find admin user.")

        admin_user.set_password(settings.ADMIN_PASSWORD)
        admin_user.save(update_fields=["password"])