At first, make sure the download link is valid. Now You can make a custom javascript function to force download from an external link.

<script>
    function downloadForce(link){
        var url = link.getAttribute("data-href");
        var fileName = link.getAttribute("download");
        link.innerText = "Downloading...";
        var xhr = new XMLHttpRequest();
        xhr.open("GET", url, true);
        xhr.responseType = "blob";
        xhr.onload = function(){
            var urlCreator = window.URL || window.webkitURL;
            var imageUrl = urlCreator.createObjectURL(this.response);
            var tag = document.createElement('a');
            tag.href = imageUrl;
            tag.download = fileName;
            document.body.appendChild(tag);
            tag.click();
            document.body.removeChild(tag);
            link.innerText="download here";
        }
        xhr.send();
    }
    </script>
     
    <a class="text-1 text-uppercase" href="#" data-href='https://i.imgur.com/U2KQsBD.jpeg' download="image.jpeg" onclick='downloadForce(this)'>download here</a>