At the moment Listing Manager supports creating custom front end forms within admin area. It is important to note that creating new fields in fields builder does not influence fields in admin. Listing fields in admin are coming from WooCommerce. You can add new fields for listing products as well but more in depth knowledge of WooCommerce is required. You can find more information about WooCommerce fields here.
You can start creating new fields in admin area under Listing Manager section. Field builder is divided into three parts Forms, Fieldsets and Fields. Forms represents one complete form e.g. Car or Job. Each forms consists from fieldsets and fieldsets are composed from fields.
So if you are going to create new front end submission type like art, first of all you have to create new form called Art. Then you can assign already existing fieldsets. When creating new objects and settings slug or ID values please use lowercase values without whitespaces. If you want to use whitespace replace it with underscore. By using not allowed characters you can easily lead to unexpected errors.
Each field identifier should start with the listing_ prefix which ensures that the values are saved. There are some special field identifiers which are handled differently and you can find them in description when creating new fields.
Information for developers. Front end forms are just regular PHP arrays which you can extend listing_manager_submission_forms and listing_manager_submission_fields filters. Both of them accepts arrays. If you are looking for implementation example please check wp-content / plugins / listing-manager / src / Logic / SubmissionLogic.php functions methods add_forms and add_general_fields. You can place your custom functions implementing filters mentioned above into child theme or custom plugin.