Can dev server be used with templated pages?

[IanVS]

I'm trying to add snowpack into an existing app, which is built using Jinja templates, python, and nginx. As far as I understand it, the html is built up at request time. But it seems like snowpack dev server wants a static index.html page to load. Am I out of luck, or is there maybe some way that I can use the proxy to hit my local nginx like I'd normally do when using webpack?