How to delete an Object useing PHP & CURL

I’m trying to delete objects useing CURL,

I’v made some changes on this code: https://www.digitalocean.com/community/questions/digitalocean-spaces-file-upload-using-curl

But I get this error:

SignatureDoesNotMatch

Please have a look on my code here and see if you can help to solve this issue.

$file = "cat.jpg";

$accessKeyId = '**********';
$secretKey = '***************';

$longDate = gmdate('Ymd\THis\Z');
$shortDate = gmdate('Ymd');


$cannonical = 'DELETE'.'host:bucket.sgp1.digitaloceanspaces.com'.PHP_EOL.'x-amz-date:'.$longDate.''.PHP_EOL.'content-length;host;x-amz-content-sha256;x-amz-date';

$cannonical = hash('sha256', $cannonical);

$string = 'AWS4-HMAC-SHA256'.PHP_EOL.''.$longDate.''.PHP_EOL.''.$shortDate.'/sgp1/s3/aws4_request'.PHP_EOL.''.$cannonical;

$signingKey = hash_hmac('sha256', $shortDate, 'AWS4'.$secretKey, true);
$signingKey = hash_hmac('sha256', 'sgp1', $signingKey, true);
$signingKey = hash_hmac('sha256', 's3', $signingKey, true);
$signingKey = hash_hmac('sha256', 'aws4_request', $signingKey, true);
$signature  = hash_hmac('sha256', $signingKey.$string, $signingKey);
$signature  = hash_hmac('sha256', $string, $signingKey);


$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_URL, 'https://bucket.sgp1.digitaloceanspaces.com/'.$file);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Host: bucket.sgp1.digitaloceanspaces.com',
        'Authorization: AWS4-HMAC-SHA256 Credential='.$accessKeyId.'/'.$shortDate.'/sgp1/s3/aws4_request, SignedHeaders=host;x-amz-content-sha256;x-amz-date, Signature='.$signature
]);

curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE');
curl_setopt($ch, CURLOPT_POSTFIELDS, $file);
$result = curl_exec($ch);
curl_close($ch);

Thanks heaps.