Custom Post Type Support

By default, the plugin only creates AMP content for posts. You can add support for other post_types using the post_type parameter used when registering the custom post type (assume our post_type is xyz-review):

add_action( 'amp_init', 'xyz_amp_add_review_cpt' );
function xyz_amp_add_review_cpt() {
	add_post_type_support( 'xyz-review', AMP_QUERY_VAR );
}

You'll need to flush your rewrite rules after this.

If you want a custom template for your post type:

add_filter( 'amp_post_template_file', 'xyz_amp_set_review_template', 10, 3 );

function xyz_amp_set_review_template( $file, $type, $post ) {
	if ( 'single' === $type && 'xyz-review' === $post->post_type ) {
		$file = dirname( __FILE__ ) . '/templates/my-amp-review-template.php';
	}
	return $file;
}

We may provide better ways to handle this in the future.