Algorithm for Finding Static Assets

I have a Play 2.6-Scala application, and I am using Webpack to bundle assets. Unfortunately, Play can’t find the assets when there is a hash in the file name.

In routes I have this:

GET /assets/*file

In a template I have the equivalent of AssetsFinder.path(fileName). All of this is in accordance with the documentation.

However, Play won’t retrieve a versioned asset. I have looked at the source code, but it still isn’t clear to me why it doesn’t work–except that I don’t have a digest file alongside. Is that the only issue? What’s the minimum I have to do in Webpack for the AssetFinder to cooperate?