Backend widgets are boxes of content that are displayed in the backend dashboard. Widgets are plug 'n play, meaning that if you upload a widget folder it is automatically loaded. A widget is defined by a folder named .widget in the end e.g. admin/mywidget.widget/. Inside the folder you need to create a configuration file config.inc.php that defines the widget and the file to load. See below for an example.
return [ 'name' => 'My App', 'file' => 'widget.inc.php', // The file to load that is holding the content 'priority' => 0, ];
<h1>Hello World</h1> <p>Lorem ipsum dolor</p>