Make sure you have compatible Hardware and reference this Debian Website: https://wiki.debian.org/NvidiaGraphicsDrivers

To install the NVIDIA Proprietary Drivers this command needs to be executed from the command line. After making sure you have run the apt update process.

sudo apt install nvidia-driver firmware-misc-nonfree

DKMS will build the nvidia module for your system, via the nvidia-kernel-dkms package.
Then re-start the computer.