download file from any url
function download(url, filename) {
fetch(url).then(function(t) {
return t.blob().then((b)=>{
var a = document.createElement("a");
a.href = URL.createObjectURL(b);
a.setAttribute("download", filename);
a.click();
}
);
});
}
download("https://get.geojs.io/v1/ip/geo.json","geoip.json")
download("data:text/html,HelloWorld!", "helloWorld.txt");