尝试使用用户ID变量输出当前“DJ”的缩略图

I'm fairly new to Wordpress and PHP and I'm currently learning PHP in particular at this stage. Could do with some help as a bit stuck due to lack of knowledge of PHP I think.

So I've installed the "Radio Station" to my Wordpress installation. All seems fine with that. There's a widget included with this plugin that is meant to display "On Air" information about the current DJ in the sidebar and also some information, including their thumbnail image.

The trouble im having is, I can't (properly i.e. dynamically) get this thumbnail to display.

With the standard installation, the plugin is apparently meant to use Gravatar avatars, but that didn't work no matter what I tried.

So I've been digging through the code most of the day, trying to figure it out and maybe find a function that would get me the right value and found the following which was relevant in the dj-on-air.php file:

if(count($djs['all']) > 0) {
    foreach($djs['all'] as $dj) {
        //print_r($dj);
        $dj_str .= '<li class="on-air-dj">';
        if($show_avatar) {
            $dj_str .= '<span class="on-air-dj-avatar">'.get_the_post_thumbnail($dj->ID, 'thumbnail').'</span>';
        }

The get_the_post_thumbnail() function doesn't seem to be working as intended for whatever reason. When I assigned the following variable and displayed it to see what was happening

$tmp = $dj->ID;

the output was "293" (without quotes) which, looking through phpmyadmin seemed to be the "ID" value from the wp_posts table which kinda made sense but explained why get_the_post_thumbnail() wasn't outputting a valid image url for the thumbnail since there is no user ID with a value of "293" - so it just returned nothing and the output html was

<span class="on-air-dj-avatar"></span>

So what I need to do is somehow get the "user ID" value for the currently "on-air" DJ and feed that into the following:

echo '<span class="on-air-dj-avatar">'.get_wp_user_avatar($dj->ID, 96).'</span>';

The above doesn't work presumably because the $dj->ID is returning "293".

get_wp_user_avatar() is a function I'm using from another plugin called WP User Avatar so I could set an avatar image manually for each User in the admin area.

If I manually enter the user ID value of "3":

echo '<span class="on-air-dj-avatar">'.get_wp_user_avatar(3, 96).'</span>';

It displays the avatar in the widget perfectly as the user ID of the DJ in question is "3". However, I need a way to do this dynamically.

I'm not too sure what $dj->ID is doing or how to maybe use that to get the "user ID" of the DJ and not the "wp_posts ID" as it seems to be giving?

I hope I've made some sort of sense here. If anyone can help it'd be greatly appreciated and if you need to see more of the source files, please let me know.

Thanks!