I’ve had a good look thru the Similar Questions for an answer and i’m looking to check if a value for a custom field key on single posts has been added using get_post_meta(); however i want to use this check on the author archive page.

This is my code in functions.php

global $wp_query;

$post = $wp_query->get_queried_object_id();

$meta  = get_post_meta( $post->ID, 'key', true );

if ( $meta ) :

However, the code won’t work in the author.php template