I may not be understanding something obvious, but I'm struggling to add a (top-level) menu item to my Wagtail based menu that hooks to a page rendered by an included app that doesn't know about Wagtail. Ideally, it is just a normal Django TemplateView with standard urlconf, though I may need to add some custom code.
If I use the custom URL in the menu editor, I get a not found from Wagtails core.serve. I've looked at snippets, wagtail hooks, RoutablePageMixin, and the custom URL in the menu editor and none seem like it accomplishes what I'm trying to do.
It may well be that I'm simply misunderstanding the docs, but is there a simple example of someone doing this? The closest I've found so far is https://www.caktusgroup.com/blog/2016/02/15/wagtail-2-steps-adding-pages-outside-cms/. I've also searched https://docs.wagtail.io/en/v2.4/advanced_topics/third_party_tutorials.html to now avail. Any guidance appreciated.
Thx, --Don