curl --request GET \
  --url https://api.deepl.com/v2/glossary-language-pairs \
  --header 'Authorization: <api-key>'

{
  "supported_languages": [
    {
      "source_lang": "de",
      "target_lang": "en"
    },
    {
      "source_lang": "en",
      "target_lang": "de"
    }
  ]
}

{
  "message": "Invalid glossary entries provided",
  "detail": "Key with the index 1 (starting at position 13) duplicates key with the index 0 (starting at position 0)"
}

{
  "message": "<string>",
  "code": "invalid_content_type"
}

{
  "message": "<string>",
  "code": "invalid_content_type"
}

{
  "message": "<string>",
  "code": "invalid_content_type"
}

{
  "message": "<string>",
  "code": "invalid_content_type"
}

{
  "message": "<string>",
  "code": "invalid_content_type"
}