Windows publish to generic provider

[KuluGary]

I want to include the ability to publish (as I've done through electron-builder before) a Windows app to a S3 bucket, in order to be able to use electron-builder's auto-upload.

I'm on the stage of being able to deploy my packed app to the storage.

I have a .sh script to start the deployment:

cordova platform add electron

echo "Setting main.js ..."
cp res/electron/cdv-electron-main.js platforms/cordova-electron/platform_www/cdv-electron-main.js 2>/dev/null
cp res/electron/cdv-electron-main.js platforms/electron/platform_www/cdv-electron-main.js 2>/dev/null

echo "Package build ..."
webpack --config webpack.config.electron.production.js && cordova build electron --release --publish=always
echo "Done."

I also have a build.json file.

{
  "electron": {
    "linux": {
      "package": [
        "dir"
      ]
    },
    "windows": {
      "publish": [
        {
          "provider": "s3",
          "bucket": "hub-staticfiles.bexfyinfra.com"
        }
      ],
      "package": [
        "portable"
      ]
    } 
  }
}

and a bucket with the following permissions:

But I don't seem able to publish my app, get the latest.yml or anything of the sort. I believe I have the correct credentials in my .aws/credentials folder too.

Any ideas how can I go about making it work?

Thank you in advance.