Save a blob (object generated in UI) locally as a file

save-object-blob.js

/**
 * Saves a Blob object as a file with the specified filename.
 * 
 * @param {Blob} blob - The Blob object to be saved.
 * @param {String} filename - The desired filename for the saved file.
 * @example
 * const foo = `
 * NAME;DESCR
 * Foo;desc1
 * bar;desc2
 * `;
 * const blob = new Blob([ foo ], { type: "text/csv" });
 * saveBlob(blob,"file.csv");
 * 
 */
const saveBlob = (blob, filename) => {

    const fragment = document.createDocumentFragment();

    const a = document.createElement("a");
    // a.style.display = "none";
    fragment.appendChild(a);

    const url = window.URL.createObjectURL(blob);
    a.href = url;
    a.download = filename;
    a.click();
    window.URL.revokeObjectURL(url);

    fragment.removeChild(a);
};

https://developer.mozilla.org/en-US/docs/Web/API/Document/createDocumentFragment

fetch('blob:https://some.blob.url').then((response) => response.blob().then((b) => saveBlob(b, 'file.ext')));