JSFiddle - React, Tailwind, and code Playground

HTML

<p class='that'>

</p>

CSS

.that{background-color:green;height:50px;width:100%;}

JavaScript

function base64ToArrayBuffer(base64) {
    var binaryString =  window.atob(base64);
    var binaryLen = binaryString.length;
    var bytes = new Uint8Array(binaryLen);
    for (var i = 0; i < binaryLen; i++)        {
        var ascii = binaryString.charCodeAt(i);
        bytes[i] = ascii;
    }
    return bytes;
}

var saveByteArray = (function () {
     var a = document.createElement("a");
    document.body.appendChild(a);
     //  a.style = "display: none"; 
    return function (data, name) {
        var blob = new Blob(data, {type: "octet/stream"}),
            url = window.URL.createObjectURL(blob);
         a.href = url;
         $(a).text('Download')
        a.download = name;
      //  a.click(); 
        
        var link = '<a target="_blank" download class="btn btn-primary downloadAttachment" href="' + url + '" >Download</a>';
$('.that').append(a)
        
        
       // window.URL.revokeObjectURL(url);
    };
}());


var sampleBytes = base64ToArrayBuffer('R0lGODlhAQABAIAAAAUEBAAAACwAAAAAAQABAAACAkQBADs');
saveByteArray([sampleBytes], 'black1x1.gif');