如何使用JavaScript获取客户端的IP地址？

fetch('https://api64.ipify.org?format=json')
  .then(response => response.json())
  .then(data => console.log(data.ip))
  .catch(error => console.error(error));

const peerConnection = new RTCPeerConnection({});
peerConnection.createDataChannel('');

peerConnection.createOffer()
  .then(offer => peerConnection.setLocalDescription(offer))
  .catch(error => console.error(error));

peerConnection.onicecandidate = event => {
  if (!event || !event.candidate) {
    return;
  }

  const ipAddress = /^\d+\.\d+\.\d+\.\d+$/.exec(event.candidate.candidate.split(' ')[4]);

  if (ipAddress) {
    console.log('Client IP address:', ipAddress[0]);
    peerConnection.close();
  }
};