Displaying Contentful content in a sidebar region on external web app

Hello Contentful. I am new to this tool. How do I embed a widget on my website that would retrieve a white paper from my content types? basically the contentful asset would appear on the sidebar region of my page. We currently embed all of . our customer case studies on our page. Heres a example See the webinar replay button. We want to do something like this and tag the content so we could control which page the offer shows up on.