Now click on the Downloads tab. All the addons in the purchased plan will be listed along with the download links. Click on the download links beside the addon which you want to download.
Once you download click the Download link, you will get a zip file for the addon. You can now install this zip file like any other plugin.
Simply go to Plugins >Add New in the WordPress Dashboard.
Click the Upload Plugin button.
You will get option to upload the plugin. Click on the choose file button and select your addon zip file.
After the file is uploaded simply click Install Now button.
Once the plugin is installed, It will ask to activate simply click on Activate Plugin button
After activating addon you need to verify the license key.