const Login = () => {
    const setToken = function(e) {
    if (
      e.origin === origin &&
      e.data &&
      e.data.command === 'token-ready' &&
      e.data.info &&
      e.data.info.token
    ) {
      localStorage.setItem('jwt', e.data.info.token);

      e.source.postMessage(
        {
          command: 'info',
          info: {
            complete: true,
          },
        },
        e.origin
      );
    }
  };

  
  window.addEventListener('message', setToken, false);

  const login = () => {
    window.open(loginUri);
  };

  return (<button onClick={login}>Login</button>
}