I'm trying to install ROS2 on a raspberry pi ver 3 running Ubuntu 22.04.1 LTS server. I copied and pasted all the lines from the ros.org installation page. All worked ok until the line

sudo apt install ros-humble-ros-base

there I get the following

pi@raspberrypi:~$ sudo apt install ros-humble-ros-base
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package ros-humble-ros-base