angular.json

{
  //...
  "projects": {
    "Flowmono-Website": {      
      "i18n": {
        "sourceLocale": "en-US",  // Default locale
        "locales": {
          "fr": {
            "translation": "src/locale/messages.fr.xlf"  // French translations
          },
          // Add more locales as needed
        }
      },
      "architect": {
        "build": {
	        "configurations": {
		        "fr": {
              "localize": ["fr"]
            }
	        }
        },
        "serve": {
          "fr": {
            "browserTarget": "Flowmono-Website:build:development,fr"  // Serve French locale
          }
        }
      }
      // ...
    }
  },
}