Here are 2 way about how to install HDMI LCD screen:

1. Desktop

1. install desktop on raspberry pi

https://octoprint.org/blog/2016/05/02/new-octopi-release-0-13-0/

The desktop subsystem is not included by default anymore since most people don’t actually use it (OctoPi is meant to run as a headless network appliance), but in case you need it, we also put a little helper script on there which will allow you to quickly

install the desktop environment. Just SSH or keyboard into your OctoPi instance, execute

sudo ./scripts/install-desktop

and then follow the instructions.

2. install firefox

sudo apt install firefox-esr

3. open http://localhost in firefox web browser.

2.Octoscreen

if you do not like desktop, you can install Octoscreen: No need for desktop, web browser... Just install and set up... Way to go! Install:

wget https://github.com/Z-Bolt/OctoScreen/releases/download/v2.5.1/octoscreen_2.5-1_armhf.deb
sudo dpkg -i octoscreen_2.5-1_armhf.deb

Config:

edit this file: /etc/octoscreen/config.
set OCTOPRINT_HOST to http://localhost
set OCTOSCREEN_RESOLUTION to at least 800x480

More info in this link: https://github.com/Z-Bolt/OctoScreen