get-list-of-tags.php

<?php

// get the contact record if one exists
$contact = \Groundhogg\get_contactdata( 'email@example.com' );
// Get a list of contact ids
$tags = $contact->get_tags();
// to get a list of ID >> Name
$tag_id_to_name = [];
// Populate the list
foreach ( $tags as $tag_id ) {
	// create a tag object based on the ID
	$tag = new \Groundhogg\Tag( $tag_id );
	$tag_id_to_name[ $tag_id ] = $tag->get_name();
}