You can use a Hook Element to add the HTML to your site.
1. Create a new Hook Element:
https://docs.generatepress.com/article/hooks-element-overview/
2. Add this as your hook content:
<?php
if (function_exists( 'is_amp_endpoint' ) && is_amp_endpoint()) {
?>
// Add your HTML or Shortcode here
<?php
}
?>
3. Select the menu_bar_items
hook
4. Check Execute PHP ( and check Execute Shortcodes if you’re using them )
4. Set the Display Rules to the Entire Site
.