Name of plugin file is divi-404-extended.zip. It can be downloaded from the link in order confirmation email. The plugin is also available for download from the My Account area. If the plugin was purchased from any vendor, the download link will be available at their website.
The second file available for download with this product is divi-404-extended-layouts.zip. It needs to be extracted and the file inside it “Divi Builder Layouts.json” needs to be imported to Divi Library. Once the layout is imported, it can be selected from the plugin settings page. Please refer to the video tutorial on how to do it.