Download local static file

I have an issue with downloading static local files in my electron app.

After building and bundling my web app (using webpack), I’m left with an index.html file and a static folder containing files which my web app is using, but on the electron app I can’t access them since their absolute path is not set as it should be. This is how I try to download the file on the renderer process:

<a href="/static/file1.csv">File1></a>

and on the main process when I catch the ‘will-download’ event I’m getting a relative path:

win.get().webContents.session.on('will-download', (event, item, webContents) => {
    log.info(`item: ${item.getURL()}`); // macOS: file:///static/file1.csv, windows: file:///c:/static/file1.csv
  });

The file isn’t getting downloaded.
I’ve read a post suggesting to use protocol.interceptFileProtocol and change the file path, but when I use this option I can’t load the index.html file at all, apparently due to chrome security policy and the chrome output is:

Electron Security Warning (Insecure Content-Security-Policy) This renderer process has either no Content Security Policy set or a policy with “unsafe-eval” enabled. This exposes users of this app to unnecessary security risks.

For more information and help, consult https://electronjs.org/docs/tutorial/security.
This warning will not show up once the app is packaged.

Not allowed to load local resource: file:///MyFolder/index.html

What is the correct way to access static files from the renderer process, corresponding to electron’s security policy (https://electronjs.org/docs/tutorial/security)?