How to get Blob from input[type="files"]?

Question

JavaScript

I want to attach a file to the constructed form:

var formData = new FormData();
... // Тут создаю нужные мне поля
formData.append("file", Blob, "test.mp3");

However, in order to do this, I first need to get my hands on the Blob.
Tell me, how can I pull out Blob from the input field with the inserted file?

Answer 1

https://developer.mozilla.org/ru/docs/Web/API/File
File inherited from Blob

Answer 2

And why exactly Blob?

const file = document.querySelector('input[type="files"]').value;
formData.append("file", file, "test.mp3");