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

[  {  "language": "AR",  "name": "Arabic",  "supports_formality": false  },  {  "language": "BG",  "name": "Bulgarian",  "supports_formality": false  },  {  "language": "CS",  "name": "Czech",  "supports_formality": false  },  {  "language": "DA",  "name": "Danish",  "supports_formality": false  },  {  "language": "DE",  "name": "German",  "supports_formality": true  },  {  "language": "EL",  "name": "Greek",  "supports_formality": false  },  {  "language": "EN-GB",  "name": "English (British)",  "supports_formality": false  },  {  "language": "EN-US",  "name": "English (American)",  "supports_formality": false  },  {  "language": "ES",  "name": "Spanish",  "supports_formality": true  },  {  "language": "ES-419",  "name": "Spanish",  "supports_formality": true  },  {  "language": "ET",  "name": "Estonian",  "supports_formality": false  },  {  "language": "FI",  "name": "Finnish",  "supports_formality": false  },  {  "language": "FR",  "name": "French",  "supports_formality": true  },  {  "language": "HU",  "name": "Hungarian",  "supports_formality": false  },  {  "language": "ID",  "name": "Indonesian",  "supports_formality": false  },  {  "language": "IT",  "name": "Italian",  "supports_formality": true  },  {  "language": "JA",  "name": "Japanese",  "supports_formality": true  },  {  "language": "KO",  "name": "Korean",  "supports_formality": false  },  {  "language": "LT",  "name": "Lithuanian",  "supports_formality": false  },  {  "language": "LV",  "name": "Latvian",  "supports_formality": false  },  {  "language": "NB",  "name": "Norwegian (Bokmål)",  "supports_formality": false  },  {  "language": "NL",  "name": "Dutch",  "supports_formality": true  },  {  "language": "PL",  "name": "Polish",  "supports_formality": true  },  {  "language": "PT-BR",  "name": "Portuguese (Brazilian)",  "supports_formality": true  },  {  "language": "PT-PT",  "name": "Portuguese (European)",  "supports_formality": true  },  {  "language": "RO",  "name": "Romanian",  "supports_formality": false  },  {  "language": "RU",  "name": "Russian",  "supports_formality": true  },  {  "language": "SK",  "name": "Slovak",  "supports_formality": false  },  {  "language": "SL",  "name": "Slovenian",  "supports_formality": false  },  {  "language": "SV",  "name": "Swedish",  "supports_formality": false  },  {  "language": "TR",  "name": "Turkish",  "supports_formality": false  },  {  "language": "UK",  "name": "Ukrainian",  "supports_formality": false  },  {  "language": "ZH",  "name": "Chinese (simplified)",  "supports_formality": false  },  {  "language": "ZH-HANS",  "name": "Chinese (simplified)",  "supports_formality": false  },  {  "language": "ZH-HANT",  "name": "Chinese (traditional)",  "supports_formality": false  } ]