Nvidia-legacy-390xx-driver issue with debian 10, after installing drivers the GPU is not working

I have an old laptop, which has the Nvidia 540M (Optimus). I installed a fresh copy of debian 10 and installed the drivers as suggested by the Debian over this link https://wiki.debian.org/NvidiaGraphicsDrivers#Version_390.132_.28legacy_GPUs.29 but the process does not work. As I’m opening the Nvidia X server settings, it shows me dialogue box states ‘You do not apear to be using the NVIDIA X drivers. Please edit your X cofig file’. After steps:-

  1. So I run Nvidia-xconfig as root, but console throws an error of command not found.
  2. I download the nvidia-xconfig with apt install Nvidia-xconfig and run it. It generates a file inside /etc/X11/xorg.conf.
  3. I restarted the system but not be able to load ito UI(Gnome) after the boot screen.
  4. So I use ctrl+alt+f2 and change the xorg.conf name and only then I will be able to login with Gnome.

How can I work around with this problem, please help.
xorg.conf file is attached-
xorg.txt (1.2 KB)