File downloaded from BlobStorage are corrupted

I have this method in my blazor web app which I use to get a files' url from my api.The files are already uploaded in AzureBlobStorage and when I try to download them directly from the URL that my API provides me, I can open them and they're all fine.

However, when I try it with my methods, the download is successful but the I cannot open them since they seem to be corrupted.

My blazor method:

public async Task DownloadStream(FileProperties file){    DisableButton = true;    try    {        var blobUrl = await _httpClient.GetBlobUrl(file.Id.ToString());        await _jsRuntime.InvokeVoidAsync("fileDownload", blobUrl, file.Name);    }    catch (Exception ex)    {        Console.WriteLine("ERROR: JS method missing... " + ex.Message);    }    DisableButton = false;}

My Javascript method that I invoke in my method:

function fileDownload(base64String, fileName) {    console.log("url=", base64String);    const a = document.createElement("a");    a.href = base64String;    a.download = fileName;    a.target = "_blank"; // Open in new tab if needed    document.body.appendChild(a);    a.click();    document.body.removeChild(a);}

What am I missing here?