Paste the code to your Tumblr website’s HTML field.
Next, go to your Tumblr website editor and find the HTML field. It is most likely in the form of an HTML/Code widget or module which you can find on the Tumblr’s editor. Add it to your page, and paste the Announcements Embed Code you’ve copied before to the HTML field.
Save and update, and that’s it, you should have Common Ninja’s Announcements widget on your Tumblr website.