Change Camera Rotation by User Input when Camera is Framing Transposer in Unity Cinemachine

CameraRotation.cs

// Problem Statment: Allow the player to modify camera orientation during runtime using key press
// Since Framing Transposer Virtual Camera Target Mode by default does not allow altering camera rotation
// This script works as solution
// After dropping the script into your project, add it to virtual camera through Virtual Camera Extention field 
// in the Virtual Camera Gameobject 

using UnityEngine;
using Cinemachine;
//using TryAgainFSM;

/// <summary>
/// An add-on module for Cinemachine Virtual Camera that locks the camera's X (or Y/ or Z) rotation
/// </summary>
[SaveDuringPlay]
[AddComponentMenu("")] // Hide in menu
public class CameraRotation : CinemachineExtension
{
    [Header("Defaut Camera Rotation")]
    [Tooltip("Lock the camera's rotation to these values as default orientation")]
    public float m_XDefaultRotation = 10f;
    public float m_YDefaultRotation = 0f;
    public float m_ZDefaultRotation = 0f;

    [Header("Camera Panning Settings")]
    public float PanCamRotationInY  = 20f; // How far can this camera pan?
    public float cameraPanSpeed = 5f;
    public float cameraResetSpeed = 20f;
    // my game input system, you don't need it
    public RPGCharacterInputSystemController c; 
    protected override void PostPipelineStageCallback(
        CinemachineVirtualCameraBase vcam,
        CinemachineCore.Stage stage, ref CameraState state, float deltaTime)
    {
        if (stage == CinemachineCore.Stage.Aim)
        {   
            var pos = state.RawOrientation;
            if (c.inputCameraPan) // use Input.GetKey here or similiar funtion to detect user input
            {
                // final look at point
                Quaternion lookAt = Quaternion.Euler(m_XDefaultRotation, PanCamRotationInY, m_ZDefaultRotation);
                // slowly rotate between current rotation to lookAt
                state.RawOrientation = Quaternion.Lerp(transform.rotation, lookAt, cameraPanSpeed * Time.deltaTime);
            }
            else
            {
                state.RawOrientation = Quaternion.Lerp(transform.rotation, Quaternion.Euler(m_XDefaultRotation, m_YDefaultRotation, m_ZDefaultRotation), cameraResetSpeed * Time.deltaTime);
            }
        }
    }

}