Signup for the account and create popup for your website by filling all the mandatory details and theme customisation.
Once the popup is created go to Edit Rating section and click on Embed button and copy the Embed link. You can also edit or delete your campaign and view stats of your campaign on this section.
Open your website index.html page or the page where you want to add popup, and paste the copied link under HEAD tag. Save your made changes and visit your website to see the popup in action.