Dolphin 7.1 how do you modify Ads form?

I can't find how to remove "country" field from Ads in the admin.

My site will be for only 1 country so the members do not need to choose country as option.

I search docs and all over the admin but no luck

/modules/boonex/ads/classes/BxAdsModule.php

around line 885 the form starts.

around line 963 is the country section

it would be good if there was a form fields editor in the admin for all forms so users could add and remove fields