def METHOD_NAME(app_configs, **kwargs):
    from django.conf import settings
    errors = []
    if getattr(settings, "WAGTAILADMIN_BASE_URL", None) is None:
        errors.append(
            Warning(
                "The WAGTAILADMIN_BASE_URL setting is not defined",
                hint="This should be the base URL used to access the Wagtail admin site. "
                "Without this, URLs in notification emails will not display correctly.",
                id="wagtailadmin.W003",
            )
        )
    return errors