download QR Code SVG when button clicked (add to page settings > custom code > footer scripts)

footer-scripts.html

<script>

document.addEventListener("DOMContentLoaded", () => {

    const buttonSelector = ".my-download-button"; 	/* change to the selector for your download button */
    const qrCodeSelector = ".my-qr-code"; 			/* change to the selector for your qr code element */
    const svgFileName = "my-qr-code";			    /* change to desired file name for the SVG to download */

  
    const button = document.querySelector(buttonSelector);
    const qrcode = document.querySelector(qrCodeSelector + ' svg');

    if (!button || !qrcode) { return; }

    button.addEventListener("click", () => {

        const source = new XMLSerializer().serializeToString(qrcode);

        const blob = new Blob([source], {
            type: "image/svg+xml;charset=utf-8"
        });
      
        const url = URL.createObjectURL(blob);
        const link = document.createElement("a");
      
        link.href = url;
        link.download = svgFileName + '.svg';
        link.click();

        URL.revokeObjectURL(url);
    });
});

</script>