Additional Field Workaround
Currently the only fields supported in LandingPage Monkey in the autoresponder form are the NAME and EMAIL fields.
Check this out in the FAQ : Can fields in addition to name and email be added in AR?
However there is a workaround for adding additional fields of your choice such as Phone, Zip code, Address etc.
You can direct your customers to the hosted form on your Autoresponder, if it has this feature, by hyperlinking your Button Text in Step 1 - Page Styling directly to the form and bypassing Step 3 - Autoresponder Integration in LandingPage Monkey.
How to get the URL to place for the Button Text Hyperlink