CMake is an one of the open-source package and the CMake can support cross-platform family of tools designed to build, test and package software. This is used to control the software compilation process using simple platform and compiler independent configuration files, generate native makefiles and workspaces that can be used in the compiler environment. 

When trying to install the obs-pulseaudio-app-capture package in my Ubuntu machine received an error like  ,

Command ‘cmake’ not found

But we can fix the error using the steps below,

$ sudo apt  install cmake

Check your CMake version using the command below,

$ cmake --version
 
cmake version 3.22.1
CMake suite maintained and supported by Kitware (kitware.com/cmake).

Once you are verified the cmake packages in your machine, execute the commad below,

$ cmake ..