Globalization Pipeline accepts any valid language code through REST APIs, tools, dashboard or plugins. Please use the language code from id in this list. For example, Globalization Pipeline accepts af as the language code of Afrikaans:
{
"name": "Afrikaans",
"id": "af",
"full": "af-Latn-ZA",
"aliases": ["af-ZA"],
"straker": "Afrikaans"
}