I'm trying to publish new podcasts via the api, I've successfully upload the mp3 and jpg, which gives 600 seconds to then publish. The podcast 'type' is required and one of the acceptable values is 'public. Here the response:

{"error":"input_params_invalid","error_description":"Episode type is invalid."}

I'm doing this in PHP. I've been successfully connecting to the API, it is not a token issue.

 $params = [
        'access_token'=> $token,
        'type' => 'public',
        'apple_episode_typeoptional' => 'full',
        'status' => 'publish',
        'media_key' => $files['audio'],
        'logo_key' => $files['image'],
        'title' => 'Good day',
        'content' => 'Time you <b>enjoy</b> wasting, was not wasted.'
    ];

    $params = http_build_query($params);

     // . '?' . $params,
    // CURLOPT_POSTFIELDS => $params
    $options = [
        CURLOPT_URL => $url . '?' . $params,
        CURLOPT_POST => TRUE,
        CURLOPT_RETURNTRANSFER => TRUE,
        CURLOPT_SSL_VERIFYPEER => FALSE
    ];
    $response = $this->getPodbean($options);

UPDATE:

This is what is holding me up. I don't think I have converted curl -v -H "Content-Type: image/jpeg" -T /your/path/file.ext "{presigned_url}" correctly. I added CURLOPT_USERPWD because without it I was getting a 403, now I get 400. I added token for good measure but it doesn't seem to affect anything one way or the other.

$imageMime = mime_content_type($image_path);

$filename = basename($image_path);
$cfile = curl_file_create($image_path, $imageMime, $filename);

//Open the file using fopen.
$fileHandle = fopen($image_path, 'r');

$options = [
    CURLOPT_URL => $presigned_url,
    CURLOPT_USERPWD => "$this->client_id:$this->client_secret",
    CURLOPT_POSTFIELDS => http_build_query(['image_upload' => $cfile, 'access_token'=> $token]),
    CURLOPT_POST => TRUE,
    CURLOPT_HTTPHEADER => http_build_query(['Content-Type' => $imageMime]),
    CURLOPT_RETURNTRANSFER => TRUE,
    CURLOPT_SSL_VERIFYPEER => FALSE
];

$this->getPodbean($options);