<?php 
add_action( 'wp_footer', function () { 
	if(is_page(20)){
?> 
<script data-cfasync="false" data-no-optimize="1" data-no-defer type="javascript/blocked" data-wpmeteor-type="text/javascript" >
    document.getElementById("myBTN").style.display = "none";
</script>
<?php 
 }
});