Wow, that was quick – thanks.
I found a helpful post here on how to add shortcodes to the sidebar: https://www.ads-software.com/support/topic/how-to-make-shortcodes-work-in-a-widget?replies=4
Yup, a vertical design would look better in the sidebar, but it works okay even with a horizontal one for now. I adjusted the width to make it work since its nicer looking than other optin forms I’ve tried. Can’t wait for the vertical designs!