Enter a name for the added media source in the lower box. Copy and paste or type in the desired repo's Media Source URL correctly to the popup location box, then click OK. Double-click on the Add source bar on the left side. Get back to System menu, click on the File manager module from the upper-left side. Click on System > Go to Add-ons tab > enable Unknown sources. Launch Kodi, from the main menu, click gear icon from the upper side of the left panel.

Skip Step 2-6 if you have already downloaded the zip file for the desired addon.

To install third-party addons, since Kodi prohibits the installation of third-party addons/repos by default for security issues, we need to set Kodi to allow installation from unknown sourcesbefore installing any addons.

This installation guide applies to third-party addons, for addons in official Kodi addon repository, you can download and install them from: Main menu > Add-ons > Download > Video Addons > Locate and click on the desired addon > Click Install.

Youtube mp3 addon