base64 to blobURL

const raw = window.atob(base64);
const rawLength = raw.length;
const blobArray = new Uint8Array(new ArrayBuffer(rawLength));

for (let i = 0; i < rawLength; i++) {
    blobArray[i] = raw.charCodeAt(i);
}

const blob = new Blob([blobArray], {type: 'applicatioin/pdf'});
const blobUrl = window.URL.createObjectURL(blob);