wordpress function to output meta tag for domain verification in head

Appearance > Themes > Theme Editor > functions.php

add_action('wp_head','ifjt_meta_domain_verify');

function ifjt_meta_domain_verify() {
?>
<meta name="facebook-domain-verification" content="67up5r2pygsmvi3sjhya25ab6m0jg3" />
// replace this line with a meta verification code
<?php
}