I have installed Vercel CLI to test a serverless function locally.
The repository is this: https://github.com/LuigiImVector/github-badge/tree/eda8e1954fc81d69142c461b89f32e9f7635f6f2

With vercel dev I started the localhost server but there is a problem. The homepage (index.html) is loaded correctly but when I go to http://localhost:3000/api or http://localhost:3000/api/index.js an error appears.

image-error

The entire error message that appears in the console is this:

Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only file and data URLs are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'c:'
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:782:11)
    at Loader.resolve (internal/modules/esm/loader.js:88:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:241:28)
    at Loader.import (internal/modules/esm/loader.js:176:28)
    at importModuleDynamically (internal/modules/cjs/loader.js:1011:27)
    at exports.importModuleDynamicallyCallback (internal/process/esm_loader.js:30:14)
    at getListener (C:\Users\luigi\AppData\Roaming\npm\node_modules\vercel\node_modules\@vercel\node\dist\launcher.js:66:24)
    at C:\Users\luigi\AppData\Roaming\npm\node_modules\vercel\node_modules\@vercel\node\dist\launcher.js:77:5
    at main (C:\Users\luigi\AppData\Roaming\npm\node_modules\vercel\node_modules\@vercel\node\dist\dev-server.js:103:14)
    at processTicksAndRejections (internal/process/task_queues.js:95:5) {
  code: 'ERR_UNSUPPORTED_ESM_URL_SCHEME'
}
Error! Failed to complete request to /api/index.js: Error: read ECONNRESET

In the site on Vercel everything works perfectly (https://github-badge-three.vercel.app/api?years=9) but in localhost does not.