Hi Dirk,
Docs are still being worked on, i will try my hardest to do a video walk through later.
For ninja forms, u need 20.0.05-beta.
1. install ninja fomrs plugin
2. Go to the add new form and select the “GeoDirectory Contact form”
Now there are a few ways to add the forms, we created a special widget/shortcode “GD > Ninja Forms” this will output a button that will open the form in a lightbox, the reason we did it via lightbox is #1 prevent caching issues, #2 it allows you to have multiples of the same form on the one page (not possible as standard)
So you can either add the widget to the details page sidebar and/or add the shortcode to the “Archive item template” page.
I am also adding a step to the setup wizard to automate all this.
Thanks,
Stiofan