The correct order of the tuple contents is this:

meta={'unique_together': [('language_code', 'field_name_here')]}

Official sources (latest version, oct/2024):

• https://django-parler.readthedocs.io/en/stable/advanced/manual-models.html?highlight=unique_together
• https://django-parler.readthedocs.io/en/stable/api/parler.models.html?highlight=unique_together