If you use Squarespace Shape Block, you can follow these steps to make it clickable.
#1. Paste this code to Website Tools (under Not Linked/Hidden Pages) > Code Injection > Footer
(If you use Personal Plan, you can also edit Site Footer > Insert a Block > Choose Markdown > Paste same code)
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('.fe-block a:contains("clickable")').addClass('text-click');
});
</script>
#2. Paste this code to Website Tools > Custom CSS
#3. Add a Text Block over entire Shape Block
#4. Add a text clickable then add link to it
Note: Do not change clickable text color. The code will make this text invisible on preview/live mode.