如何使用终端安装’add-apt-repository’?

我想安装:

add-apt-repository ppa:ricotz/testin 

它显示:

 The program add-apt-repository is currently not installed. You can install it by typing: sudo apt-get install python-software-properties 

我现在应该怎么做?

试试这些:

 sudo apt-get install software-properties-common 

和/或

 sudo apt-get install python3-software-properties 

和/或

 sudo apt-get install python-software-properties