def translation_allowed_language(select_language: str) -> str:
    "Check for feincms specific set of allowed front end languages."
    if settings.FEINCMS_FRONTEND_LANGUAGES:
        language = select_language[:2]
        if language not in settings.FEINCMS_FRONTEND_LANGUAGES:
            select_language = PRIMARY_LANGUAGE

    return select_language
Check for feincms specific set of allowed front end languages.
feincms/extensions/translations.py