import { kill, killer } from 'cross-port-killer';

kill(9090).then(pids => {
  console.log(pids)
})

// you could also kill pids manually if you know them... this would save you bringing up another lib, you are welcome.

killer.killByPid(12345).then(() => console.log('done'))
killer.killByPids([12345, 54321]).then(() => console.log('done'))