what I want to achieve is to install Firefox beta channel to update the current version so after running this command
sudo apt-repository ppa:mozillateam/firefox-next
I got this error
sudo: apt-repository: command not found
I've searched a lot to fix this, I found to fix this is to install
sudo apt-get install python-software-properties
which is printing the following
Reading package lists... Done
Building dependency tree
Reading state information... Done
python-software-properties is already the newest version (0.96.9debian1).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
and I've tried what is mentioned in this thread and nothing worked. I can't find any solution for this.