Add item to petiton

Hello! I just bought a petition theme to help start a small petition, we bought this theme

But we need to make some modifications to it, I’ve only used another CMS and only know how to do that there. I’ll need to add another field to the petition form, namly ‘position’

I tried adding it as an $options = array( in the array.options.php file, but could not see any of the changes I made on the actual website.

How can I add items to this form? I’ll be happy to provide more data that could help!