app.js

const { AsyncLocalStorage } = require('async_hooks'); 
const asyncLocalStorage = new AsyncLocalStorage(); 

app.get('/', (request, response) => { 
  const requestId = uuid(); 
  
  asyncLocalStorage.run(requestId, async () => { 
    // entering asynchronous context
    log('Start processing');
    await emailService.notify(request.body.emails);
    response.writeHead(200); 
  }); 
});