Last active device Unity https://forum.unity.com/threads/detect-most-recent-input-device-type.753206/

InputDeviceChangeHandler.cs

    using UnityEngine;
    using UnityEngine.UI;
    using UnityEngine.InputSystem;
    using UnityEngine.InputSystem.Users;
     
    // add this into built-in button you can create from menu: UI/Button
    public class InputDeviceChangeHandler : MonoBehaviour {
       // refs to Button's components
        private Image buttonImage;
     
       // refs to your sprites
        public Sprite gamepadImage;
        public Sprite keyboardImage;
     
        void Awake() {
            buttonImage = GetComponent<Image>();
            PlayerInput input = FindObjectOfType<PlayerInput>();
            updateButtonImage(input.currentControlScheme);
        }
     
        void OnEnable() {
            InputUser.onChange += onInputDeviceChange;
        }
     
        void OnDisable() {
            InputUser.onChange -= onInputDeviceChange;
        }
     
        void onInputDeviceChange(InputUser user, InputUserChange change, InputDevice device) {
            if (change == InputUserChange.ControlSchemeChanged) {
                updateButtonImage(user.controlScheme.Value.name);
            }
        }
     
        void updateButtonImage(string schemeName) {
           // assuming you have only 2 schemes: keyboard and gamepad
            if (schemeName.Equals("Gamepad")) {
                buttonImage.sprite = gamepadImage;
            }
            else {
                buttonImage.sprite = keyboardImage;
            }
        }
    }