show AMP link Wordpress

#single.php

<link rel="amphtml" href="<?php if ( get_option('permalink_structure') ) { echo get_permalink($post->ID); } ?>amp/"><center><a rel="follow" href="<?php if ( get_option('permalink_structure') ) { echo get_permalink($post->ID); } ?>amp/"><?php if ( get_option('permalink_structure') ) { echo get_permalink($post->ID); } ?>amp/</a></center><hr>

#index.php

<div class="w3-center w3-padding-0 w3-white w3-full w3-content"><link rel="amphtml" href="<?php echo get_home_url(); ?>/amp/"><a rel="follow" href="<?php echo get_home_url(); ?>/amp/"><?php echo get_home_url(); ?>/amp/</a></div><hr>

#page.php

<hr><div align="center"><link rel="amphtml" href="<?php if ( get_option('permalink_structure') ) { echo get_permalink($post->ID); } ?>amp/"><a rel="follow" href="<?php if ( get_option('permalink_structure') ) { echo get_permalink($post->ID); } ?>amp">