PHP - send file via curl with https - php

Question

I am trying to send file via curl, but keep getting this error:
PHP Notice: Array to string conversion in /home/sasha/Documents/OffProjects/test/index.php on line 26
This is my code at the moment:
$target_url = 'https://address';
$file_name_with_full_path = realpath('mpthreetest.mp3');
$post = [
'textNote' => 'This is test',
'audioFile' => '#'.$file_name_with_full_path,
'department' => 'Test',
'timeDetected' => round(microtime(true) * 1000),
'subjectLine' => 'Test Test',
'recipients' => ['phone-number' => '111111111']
];
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$target_url);
curl_setopt($ch, CURLOPT_PORT, 443);
curl_setopt($ch, CURLOPT_POST,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch,CURLOPT_FOLLOWLOCATION, true);
$result=curl_exec ($ch);
curl_close ($ch);
echo $result;
How can I make this working?

Answer 1

You can't have an array as a value, it's trying to convert the post data into a string. Check what the website you are posting to is expecting for "recipients", my guess would be some form of JSON string.

Answer 2

When you pass an array to CURLOPT_POSTFIELDS it will try to build a form-data content (see http://php.net/manual/en/function.curl-setopt.php for details).
But you have nested arrays here:
....
'recipients' => ['phone-number' => '111111111']
...
and this cannot work. You'll have to find a different way to pass multiple values as recipients, either as a JSON string as #fire mentioned, or with a serialized value, or whatever transformation you prefer.