Need help to add third party widget directly to a page, NOT in an iframe.

I have tried added the code into the Tracking & Analytics, head part of the page. Sadly, this just breaks the display. I’ve tried add the http: or https: to see if that fixed the calendar spud so it will display.

Can anyone tell me if adding or creating a custom widget or app is possible? I just need something to house the code directly, then add it to the page so it is NOT in an iframe.