const { createElement: el } = wp.element;
const registerPlugin = wp.plugins.registerPlugin;
const PluginPostPublishPanel = wp.editPost.PluginPostPublishPanel;

function TestPostPublishPanel() {
	return el(
		PluginPostPublishPanel,
		{
			className: 'my-panel',
			title: 'My panel title',
			initialOpen: true
		},
		el( 'p', {}, `Hello, context!` )
	);
}

registerPlugin( 'test-post-publish-panel', {
    icon: 'pets',
	render: TestPostPublishPanel,
} );