QIWI API PHP 400 BAD request

Господа! Выдало 400 ошибку, не понимаю в чем проблема, уже 3 й день не могу решить проблему.

<?php
$secret_key = 'eyJ2ZXJzaW9uIjoiUDJQIiwiZGF0YSI6eyJwYXpbl9tZXJjaGFudF9zaXRlX3VpZCI6IjBsNWhsby0wMCIsInVzZXJfaWQiOiI3OTg4NTg4NDk3OCIsInNlYJldCI6IjNkZWJiZjJmM2VlZjU2NjJhOTRmYmFkMjRhYzQ1MGRkMTY0YTQ1ZjE5MjYyMzI4NzZlOWFiMGE2NjdmZTdlM2MifX0=';

$billId = 'cc961e8dd4d64f02b7372297e51fb48e-12342';
$data = [
  'amount' => 1.00,
  'currency' => 'RUB',
  "exporationDateTime" => '2021-06-02T08:44:07+03:00',
];

$headers = ["accept: application/json", 
"content-Type: application/json",
"Authorization: Bearer $secret_key"];

$url = "https://api.qiwi.com/partner/bill/v1/bills/$billId";

$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, "https://api.qiwi.com/partner/bill/v1/bills/$billId");
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT");
curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

$out = curl_exec($curl);
$binary = json_encode($out);

curl_close($curl);
print_r($out);

?>