electron/docs/fiddles/system/protocol-handler/launch-app-from-URL-in-another-app/preload.js

// All of the Node.js APIs are available in the preload process.
// It has the same sandbox as a Chrome extension.
const { contextBridge, ipcRenderer } = require('electron')

// Set up context bridge between the renderer process and the main process
contextBridge.exposeInMainWorld(
  'shell',
  {
    open: () => ipcRenderer.send('shell:open')
  }
)