You can use this code to Website > Website Tools > Code Injection > Footer
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("span.course-item__course-action-button-text.course-item__course-action-button-text--active").html(function() {
return $(this).html().replace("Start Course", "Start Module");
});
});
</script>
