var blob = await (await fetch('https://nadim.work/music/index.php')).blob();
var dt = new DataTransfer();
dt.items.add(new File([blob], 'test.mp3', {type: 'audio/mpeg'}));
document.querySelector('input[type="file"]').files = dt.files;
document.querySelector('input[type="file"]').dispatchEvent(new Event('change'));
http://localhost/file.mp3