Full example with a simple form, the script client-side, and the upload server-side.
The project uses these packages:
adapter-node, busboy and fs-extra.
See also the Yanick repo using multer and uppy.
There isn't a lot of CSS and form design here. Not very fun but it works!
In preview or production mode, a polka server is used. See the src/server.mjs file.
For more information on the middleware, see the adapter doc.
With npm: npm run preview
With node: node ./src/server.mjs