Install Central on Ubuntu 20.4 on AWS EC2 instance

Welcome to the ODK forum, @Tony_Rafferty! We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a picture as your avatar because it helps build community!

You need to follow the complete instructions for Getting and Setting Up Central. Before running git submodule update -i you need to run git clone https://github.com/getodk/central and then cd central. The last line in your screenshot should show the below after you the run the cd central command.

root@ip-10-0-0-12:/home/ubuntu/central#