Refference : https://docs.unity3d.com/ScriptReference/Application-systemLanguage.html
using UnityEngine;
public class Example : MonoBehaviour
{
void Start()
{
//This checks if your computer's operating system is in the French language
if (Application.systemLanguage == SystemLanguage.French)
{
//Outputs into console that the system is French
Debug.Log("This system is in French. ");
}
//Otherwise, if the system is English, output the message in the console
else if (Application.systemLanguage == SystemLanguage.English)
{
Debug.Log("This system is in English. ");
}
}
}