xhttp.open("GET", "https://api.example.com" + file, true);
    xhttp.setRequestHeader("content-type", "application/zip");
    xhttp.responseType = "blob";
    xhttp.onload = function (event) {
        var blob = xhttp.response;
        //checking file size
        var blobSize = xhttp.response.size;
         (xhttp.response.size > 0) {
            var link = document.createElement('a');
            link.href = window.URL.createObjectURL(blob);
            link.dataset.downloadurl = ['text/plain', link.download, link.href].join(':');
            link.download = fileName;
            link.click();
        }

I have deployed it on a server but when I try to access that from the server, the zip files download without any problem. When I try to download from client-server, the file gets corrupted.

The file can be only downloaded with the server's approved IP address. I assume when I try to download the file on the client side, the file doesn't pass through the server IP address.