Use:

• Edit property string dialogTitle i18n.tr("") and property string descriptionPrepend: i18n.tr("") in qml file
• Add downloadinterceptor to the project
• Add import Ubuntu.Components.Popups 1.3 to the main qml and call the download with PopupUtils.open(downloadingDialog, [id of the page], { "fileName" : [name of the file or variable] })