myip.coffee/script.js

function getMyIP() {
    const domain = window.location.hostname.replace(/^www\./, '');

    fetch('https://ipv4.' + domain)
        .then(response => response.text())
        .then(ipv4 => document.getElementById('ipv4').textContent = ipv4)
        .catch(err => {
    		console.log(err);
    		document.getElementById('ipv6').textContent = `Not available!`
    	});

    fetch('https://ipv6.' + domain)
        .then(response => response.text())
        .then(ipv6 => document.getElementById('ipv6').textContent = ipv6)
        .catch(err => {
    		console.log(err);
    		document.getElementById('ipv6').textContent = `Not available!`
    	});
}

document.addEventListener('DOMContentLoaded', () => {
    getMyIP();
});