Simple script used to identify the Unity inputs from a controller (where documentation lets you down)

GetButtonsDown.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GetButtonsDown : MonoBehaviour
{
    string[] joysticks;
    int joysticksCount = 0;
    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        joysticks = Input.GetJoystickNames();
        if (joysticks.Length != joysticksCount)
        {
            joysticksCount = joysticks.Length;
            Debug.LogError($"Joysticks updated, Count {joysticksCount}");
        }
        foreach (KeyCode key in Enum.GetValues(typeof(KeyCode)))
        {
            if (Input.GetKeyDown(key))
            {
                Debug.LogError($"Key {key.ToString()} Pressed");

            }
        }

        for (int i = 0; i < 20; i++)
        {
            var axis = Input.GetAxis($"AXIS_{i.ToString()}");
            if (axis != 0)
            {
                Debug.LogWarning($"Axis {i} Pressed");
            }
        }
    }
}