server.js

const fastify = require('fastify').default // npm install fastify
let sessionId = 0

async function fireAndForget () {
  const server = fastify()
    .route({
      url: '/login',
      method: 'POST',
      handler: async (request) => {
        const { username } = request.body
        return { token: `${username}-${++sessionId}` }
      }
    })
    .route({
      url: '/protected-route',
      method: 'GET',
      handler: async (request, reply) => {
        const { authorization } = request.headers
        if (!authorization || authorization.indexOf('foobaer') < 0) return reply.status(401).send({ error: 'No token provided!' })
        return { usedToken: authorization }
      }
    })

  await Promise.all([
    server.listen(8080, '0.0.0.0'),
    server.ready()
  ])

  server.log.info('Ready to receive requests')
}

fireAndForget()
  .then(() => console.log('done'))
  .catch(console.error)