Driver for Ubuntu 18.04 LTS that supports GTX 1050 TI graphics card

The proprietary Nvidia graphics driver can be installed in Ubuntu 18.04 from the terminal with the following commands:

sudo ubuntu-drivers autoinstall  
sudo reboot    

When installing a proprietary graphics driver, it is not necessary to uninstall the built-in open source graphics driver. The two graphics drivers can be installed alongside each other allowing the open source graphics driver to be used as a fallback alternative in case there is a problem using the proprietary graphics driver.

The ubuntu-drivers autoinstall command installs drivers that are appropriate for automatic installation including their dependencies, and the Nvidia driver will also be updated automatically when an update is available.

The attached screenshot shows that the NVIDIA 390.87 driver is running my GeForce GTX 1050 Ti card.

I installed this driver from the graphics-drivers ppa thusly:

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo apt install nvidia-384 nvidia-settings

Note: this is what I did, and 384 is supposedly a transitional package; you may be able to install nvidia-390 directly.