curl -X DELETE "https://api.mycentralino.com/v1/calendar/bookings/91" \
  -H "X-API-KEY: sk_mycentralino_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
      "reason": "impegno di lavoro"
  }'

<?php
$data = [
    'reason' => 'impegno di lavoro'
];

$ch = curl_init('https://api.mycentralino.com/v1/calendar/bookings/91');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'DELETE',
    CURLOPT_POSTFIELDS => json_encode($data),
    CURLOPT_HTTPHEADER => [
        'X-API-KEY: sk_mycentralino_your_api_key',
        'Content-Type: application/json'
    ]
]);
$response = curl_exec($ch);
curl_close($ch);
print_r(json_decode($response, true));

import requests

headers = {'X-API-KEY': 'sk_mycentralino_your_api_key'}
data = {"reason": "impegno di lavoro"}
response = requests.delete('https://api.mycentralino.com/v1/calendar/bookings/91', headers=headers, json=data)
print(response.json())