The project is currently open for backers with credits. You can't add anything to your pledge because you don't have any.
To celebrate the New Year and new adventures I am participating in Kickstarter Make 100. I'll be making 100 limited edition enamel pins of my character "The Frog Pope" along with offering some deals on miniatures and digital downloads.
Credits to your account are all funds paid to Kickstarter, this includes the amount paid in shipping and any bonus support. The Pledge Manager is an easy way to modify you pledge by adding additional items and covering any cost difference from the pledge you made on Kickstarter. Some items may cause your estimated fulfillment date to change based on production or manufacturing. As always, please reach out to me if you have any questions.