Unable load predefined template.

I want to show a predefined template when users open grapesJs something like this: Storage manager. HTML: <div id="gjs" style="height:0px; overflow:hidden"></div> <script src="app.js"></script>

javascript in app.js:

// Set up GrapesJS editor with the Newsletter plugin
const LandingPage = {
	html: '<div> style="background-color="red"; height="100px"; width="100px"</div>',
	css: null,
	components: null,
	style: null,
};
components: LandingPage.components || LandingPage.html,
	style: LandingPage.style || LandingPage.css,
	clearOnRender: true,
	storageManager: {
		id: 'gjs-',
		type: 'local',
		autoload: true,
		autosave: true,
		storeComponents: true,
		storeStyles: true,
		stepsBeforeSave: 1,
		// contentTypeJson: true,
	},

Result: Blank editor