After purchase we send you a mail with a download link to a file which is called mashshare-pluginname.zip.
To install this, go to your WordPress dashboard, go to Plugins → Add New. From there you’ll see an option for “Upload”. Click the “Browse” button, navigate your computer files and select the .ZIP file for your downloaded extension. Once it’s uploaded, click the “Activate” link.
After that you find your new Add-On settings under Settings → Add-On Settings