If Ubuntu didn't find any drivers automatically,  you can try installing drivers manually. Follow the steps below for NVIDIA GPUs:

1. Add the official PPA for NVIDIA drivers:

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update

2. Install the recommended NVIDIA driver:

sudo apt install nvidia-driver-XXX

For this step, check with the latest driver version shown for your GPU by "ubuntu-drivers devices", the replace the "XXX" with the driver version you find.

3. Reboot your system:

sudo reboot

 When you reboot your system, there will be a window asking you to input the password you set before rebooting. When the system reboot successfully, check with"nvidia-smi".

4.Check BIOS Settings (For laptops)

If you're using a laptop, it's possible that your system is set to use the integrated graphics (like Intel) by default. You can:

• Reboot your computer and enter the BIOS/UEFI setup.
• Look for settings like "Hybrid Graphics," "Discrete Graphics," or "Switchable Graphics."
• Change the setting to Discrete Graphics to force the use of your dedicated GPU.

5. Force Re-detection of Hardware

You can try forcing Ubuntu to re-detect your hardware by running:

sudo update-pciids

This will update your PCI IDs, potentially helping Ubuntu recognize your GPU.

Once you've gone through these steps, check again if the drivers are being detected with:

ubuntu-drivers devices