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