networking - Cannot access PPA... please check your internet connection

i've tried to add a repository with:

sudo apt-add-repository ppa:gottcode/gcppaCannot access PPA

but the system echoed:

Cannot access PPA (https://launchpad.net/api/1.0/~gottcode/+archive/gcppa) to get PPA
information, please check your internet connection.

even though my internet connection is working fine.

To install Kapow, you need to download the 32bit version, or the 64bit version.

Once downloaded ( probably the Downloads folder), just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, navigate to the download location, and run the command(s) below:

sudo dpkg -i 

Once the installation is done, search for Kapow in Dash, and click on it.