Choose Insert, then More Gadgets.
In the Google Sites Editor, find the Insert menu, and open it. You should see a list of available components and gadgets you can add to your site, like Images, Links, and Tables. Find the More Gadgets option, and click it. This will allow you to add customizable tools like POWr Form Builder to your site.
Copy and Paste
The Gadget manager will appear. Choose Add Gadget by URL. Then copy and paste this exact URL into the box. Click Add to finish.
Adjust Height and Width
Now that you’ve added your new, customizable Form Builder Widget to your Google Sites page, you’ll probably want to adjust the size and shape of the Widget. Use the options in the pop-up to choose a height and width for your plugin. You can also choose to add a border, scrollbar, or title around your Form Builder Widget, but we don’t recommend it. You’ll have more editing controls directly through the plugin.
Set up POWr Form Builder
Go to your live Google Sites web page and select the Settings Icon in the top right corner of your Form Builder Widget.
In the POWr Editor, click Import Existing Form Builder, find Form Builder- and click Copy.