Customize your form inside MailChimp and then click "View code"
From the popup, copy the entire code and head back to Flauntly
Open your Flauntly landing page, and click on the settings icon
Paste your MailChimp Subscriber Popup form code into the footer custom code field
You are all set. Now the form should show up on your landing page. Make sure to refresh your page or clear your cache.