Unable to download the ros-tutorials for ROS Melodic

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Hi everyone, I am new to ROS and I am trying to follow the tutorials. I tried to download the the ros-melodic-ros-tutorials package for melodic with the following command:

$ sudo apt-get install ros-melodic-ros-tutorials

but I end up with the following error:

E: Unable to locate package ros-melodic-ros-tutorials

Any idea on how to fix this? I did look for solution and I found someone with the same issue but no answer.

Edit: I tried to install other package like rqt to use rqt_graph and i still get the Unable to locate package issue.