To add the block, simply log in to your Concrete CMS site and access the editing toolbar located at the top of your pages. On the left side of the toolbar, you'll find the plus (+) icon, which opens the content panel. Click on the plus icon to add blocks, stacks, and saved clipboard blocks to the current page. Select the Countdown Block and fill in the 'End date' field with your desired end date. Save the changes, and the dynamic countdown timer will be displayed on your website.