/ / vue.config.js
module.exports = {
chainWebpack: config = > {

config
  .plugin("html")
  .tap(args => {
    args[0].template = "/Users/username/proj/app/templates/index.html"
    return args
  })

}
}

is the official example:
when I need to generate other index.html templates. Html;
then how to configure login.html to generate index.html;