Before getting in touch, check to see that we haven't answered your question previously.
Your license key is more than likely accurate, but sometimes people copy extra characters unknowingly when using the 'Copy and Paste' function. Try typing in your license key manually. If this doesn't work, send us a temporary admin login to your account and we can bypass this for you. Make sure to change your password after!
Sorry, but OptinSkin is only a plugin for Wordpress. Though it's possible to get your designs working on a static HTML site, you wouldn't have any backend features at all, and would have to edit things in Wordpress.
It's possible to make changes to every Skin by going to 'Manage Designs' on your left-side admin menu and viewing the CSS and HTML of each Skin. However, changes to HTML & CSS (like adding additional fields or more form customisation) is not something that we can support via our helpdesk. This is purely due to a time constraint and how much work would be involved custom-editing HTML for thousands of customers.
To contact us, please send an email to firstname.lastname@example.org