Create Post Programmatically - Image?

$feedData = [
    'title' => 'Post Title',
    'message' => 'Post Content', // in markdwon format.
    'space_id' => 1, // 1 is the space id
    'user_id' => 1, // 1 is the user id
];

// Additional Optional Data attribues
// for youtube or any other embeded video
$feedData['media']['url] = 'https://www.youtube.com/watch?v=video_id'; // youtube video url
$feedData['media']['type'] = 'oembed';

$feed = \FluentCommunity\App\Services\FeedsHelper::createFeed($feedData); // this will return $feed Model or \WP_Error

if(is_wp_error($feed)) {
    // it's an error
} else {
    // it's a success
    $createdFeedId = $feed->id;
    $permalink = $feed->getPermalink(); // full url of the feed
}

I have gotten this to work, but i'd like to use an 'image' in addition to the 'oembed'; I've tried 'image' or 'image/jpg' with the url to the image, but nothing works. i've also looked at the database and tried the 'featured_image' field, but that was a no-go. Any help would be appreciated.