helpful_is_amp()
Help: If you do not know how to execute or save your own PHP code, you can find help here: How to execute PHP code on your WordPress website
This function checks if an AMP plugin is installed and the current page uses AMP. In the positive case true and otherwise false is displayed.
This function is mainly used to hide Helpful on AMP pages. But you can also use this function to use it in your theme.
<?php
if ( helpful_is_amp() ) {
echo 'Hi! Helpful is not working!';
}