“populate with post type” option with checkbox

Hi,

we need some help expand our gravity forms. We need to have checkboxes, where the content comes from an custom post typ. With the plugin “Gravity forms + custom post typ“ we created a feed in the settings and we’ve tried to insert a checkbox field, but there is no possibility to populate with post type. This option is only working with a dropdown menu.

We need a solution to have the “populate with post type“ option with a checkbox. Does anyone have an idea to solve that? Or how we can implement our own php code?

Thanks & best regards