How to insert custom html through jquery using plugin-api events

I have tried to add custom html through jquery using plugin api events like api.onAppEvent(), api.decorateWidget(), etc…, in Edit CSS/HTML >> /head section. But, the events which i tried is not triggering the jquery on page load.

So, i am little bit confused about what event need to use. Because that event should trigger the jquery throughout the site on page load instead of blocking the scripts on particular pages.

Here is the code which i tried,