Turtlebot3 Unable to locate package ros-noetic-joy

[3dokki]

Turtlebot3 Unable to locate package ros-noetic-joy

[AnhHazz]

Have you installed ros-noetic yet?
If yes, maybe you haven't setup your computer to accept software from packages.ros.org yet.
Try this in your terminal:
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt install curl # if you haven't already installed curl
curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
then
sudo apt update

After those commands run your apt-get install again and see whether it solved