How to export functions in a another function?

To serve my app as a microfrontend with qiankun, I need to export these three functions in main.ts file.

export async function bootstrap () {
  // ...
}

export async function mount (props) {
  // ...
}

export async function unmount () {
  // ...
}

What I am trying to achieve is, how can I export these functions in another function?

serveMicroApp({
  onMount: (props) => { /** */ },
  onBootstrap: () => { /** */ }
  onUnmount: () => { /** */ }
})

So, how should be the content of serveMicroApp function to achieve the same thing as above (first code block)?