Select the Insert section then click More Gadgets.
Open up the Insert menu in the Google Sites Editor You should be able to see a list of available gadgets you can install on your site, including Tables, Links, and Images Select More Gadgets. This lets you add editable tools such as the POWr Birthday Countdown to your page.
Copy and Paste URL
You will see the Gadget manager. Click on Add Gadget by URL. Then add this exact URL into the field. Click Add to finish.
After you add your new Birthday Countdown Widget to your page, you're probably going to want to adjust the shape and size of your Widget. Using the options in the pop-up window, choose the height and width of your plugin. We don't recommend it, but you can insert a scrollbar, title or border to your Birthday Countdown Widget. You'll have more control while editing right through the plugin itself.
Set up POWr Birthday Countdown
Visit the live Google Sites web page and click the Settings Icon in the top right corner of your Birthday Countdown Widget.
In the POWr Editor, click Import Existing Birthday Countdown, find Birthday Countdown- and click Copy.