I am working with Wagtail CMS (version 6.1) and have implemented a PageListingViewSet to list news items, which inherit from the Wagtail page model. Everything functions correctly, but when I click the button to create a new news item, Wagtail prompts me to choose the parent page.

Given that I only have one “news index page,” I want to avoid having to select this parent page manually each time a new news item is created. How can I automatically select the single NewsIndexPage instance when creating a news item?

class NewsIndexPage(Page):
    ...
    # Only one news index page
    max_count = 1
    # 
    subpage_types: list[str] = [
        "NewsItem",
    ]

class NewsItem(Page):
    ...
    # Only allow news under news index page
    parent_page_types = [
        "NewsIndexPage",
    ]

class NewsItemViewSet(PageListingViewSet):
    model = NewsItem
    menu_label = "News Items"
    icon = "list-ul"
    add_to_admin_menu = True