How to add fields to the ticket list view in the Freshdesk portal?

We would like to add fields from the ticket to Portal view ticket list, especially the ticket_list snippet. In it we would need to show additional standard fields like type and closed on as well as custom fields.

Moreover we would like to change the display of a single ticket from “card” to “list”, similar to the option in the agent interface.

Any ideas would be highly appreciated.

Tassilo