From version 1.1.2, we added new custom field system. Which is easier for you to add new custom fields on Submit/Edit listing page. You can also enable the for for filter form ( no need to customize by php code )

Go to edit your listing type post to add new custom field on Custom Fields meta panel

Note: make sure that you must use lowercase letters and _ for field name field.

After add custom fiels and save change, the fields will be visible for use on Fields -> Listing tab.

Drags fields from right to left side panel to add fields to Submit/Edit listing page. ( author are now able to add data for the fields )

There is also new Custom Field element under CUSTOM category to get the custom field value and display it on single listing page or card view.

Use Custom Field element under FILTER category to add the custom field to filter form ( Hero, Results page and header form )

Edit custom filter fields.

And how it looks on front-end