Why does an error occur when working with the VK API?

Question

PHP

Greetings. The goal is to change the photo of the VK chat, for this, as it is written in the documentation , you need to do the following:

Upload the file to the upload_url address obtained in the previous paragraph by forming a POST request with the file field. This field must contain an image in multipart/form-data format.
To save the photo, call the messages.setChatPhoto method, passing in the file parameter the contents of the response field obtained in the previous step.

Here is my php code for post request:
$ch = curl_init($upload_url);
$curlfile = curl_file_create(__DIR__.DIRECTORY_SEPARATOR.'1.jpg');
$data = array("file"=>$curlfile);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLINFO_HEADER_OUT, 1);
$content = curl_exec($ch);
Further, vk api, when executing the messages.setChatPhoto method, returns error 22: "Upload error: photo was not resized". What could be the problem?

Answer 1

This field must contain an image in multipart/form-data format.

curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    "Content-Type:multipart/form-data"
));