Paste this in Site Settings > Custom Code > Footer Code
<script>
Webflow.push(function() {
$('.copyright-year').text(new Date().getFullYear());
});
</script>
To create an inline span in a paragraph or text block, select the text and click the 4th menu item.
Now give a class copyright-year
to that span that you want to display the current year.
Publish and view the site in your web browser (this doesn’t work in your designer preview)