Add follow button on regular page (single.php) – not showing

Hi!

I just placed the code I found here:
https://github.com/r-a-y/buddypress-followers/wiki/Add-a-follow-button-on-a-regular-WP-page

<?php
if ( function_exists( 'bp_follow_add_follow_button' ) ) :
    if ( bp_loggedin_user_id() && bp_loggedin_user_id() != get_the_author_meta( 'ID' ) ) {
        bp_follow_add_follow_button( array(
            'leader_id'   => get_the_author_meta( 'ID' ),
            'follower_id' => bp_loggedin_user_id()
        ) );
    }
endif;
?>

But nothing happens. Even not showing up in the code..?

If I change "get_the_author_meta( 'ID' )" to "the_author_meta( 'ID' )", at least I get the ID shown up. But that was just to figure out if the ID could be shown somehow.

https://www.ads-software.com/plugins/buddypress-followers/