A brief script that will log you into Bluesky and post 'Hello, world!'. It saves the session info to bsky.tokens so you can continue to post

post2bluesky.php

<?php

# Login info, set an app password at https://bsky.app/settings/app-passwords
$password = 'p4ssw0rd';
$handle   = 'your.handle';

# URL and data for creating a session
$apiKeyUrl ='https://bsky.social/xrpc/com.atproto.server.createSession';
$apiKeyPostData='{"identifier": "'.$handle.'", "password": "'.$password.'" }';

# If the details have been saved, used them
if (file_exists('bsky.tokens')) {
    $apiData = json_decode(file_get_contents('bsky.tokens'), true);
# Else, fetch and set the data
} else {
    # cURL to login
    $ch = curl_init();
    $allHeaders = array();
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $apiKeyPostData);
    curl_setopt($ch, CURLOPT_URL, $apiKeyUrl);
    $apiData = json_decode(curl_exec($ch), true);
    curl_close($ch);
    # Store the token content so we don't have to keep logging in
    file_put_contents('bsky.tokens', $apiData);
}

# Store the DID and JWT
$did = $apiData['did'];
$key = $apiData['accessJwt'];

# Created at date
$date = date('Y-m-d\TH:i:s.Z\Z');

# URL and data for creating a post
$feedPostUrl='https://bsky.social/xrpc/com.atproto.repo.createRecord';
$feedPostData='{"collection":"app.bsky.feed.post", "repo":"'.$did.'", "record":{"text":"Hello, world!", "createdAt":"'.$date.'", "type":"app.bsky.feed.post"}}';

# cURL to post
$ch = curl_init();
$allHeaders = array();
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type:application/json', 'Authorization: Bearer '.$key));
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $feedPostData);
curl_setopt($ch, CURLOPT_URL, $feedPostUrl);
$postData = json_decode(curl_exec($ch), true);
curl_close($ch);

# If it was posted OK
if ($postData['validationStatus'] == 'valid') {
    $postIdParts = explode('/', $postData['uri']);
    $postId = end($postIdParts);
    # Display a link to the post
    echo '<a href="https://bsky.app/profile/'.$handle.'/post/'.$postId.'">View post on Bluesky</a>';
}

Sorry, not something I can do right now but if I get time to upload a new gist for image uploads I will. To help get you started, the postData would just be the contents of the image file sent to the end point I shared before. You'll get a response with details of the face that you can then add to the next API call when you're making your pots.