AWS OVH (aws/aws-autoloader)

I can connect to my ovh storage:

$s3Client = new S3Client('profile' => 'default','endpoint' =>'http://storage.sbg.cloud.ovh.net', 'region' => 'SBG','version' => latest','credentials' => array('key' => $key,'secret' => $secret,)]);
and list all my containers

$result = $s3Client->listBuckets();var_dump($result):wink:
But I cannot create a new one:

$s3Client->createBucket(array('Bucket' => 'cont1',));
=> So I reate it on OVH web interface :swift,SBG,private,cont1. When I would like to upload a file in this new container :

$result = $s3Client->upload('cont1', 'test.123', fopen($file_name, 'rb'), 'public-read');
I get :

PHP Fatal error: Uncaught exception 'Aws\S3\Exception\S3Exception' with message 'Error executing "PutObject" on "http://moncontainer.storage.sbg.cloud.ovh.net/test.zip";
AWS HTTP error: Client error: `PUT http://moncontainer.storage.sbg.cloud.ovh.net/test.zip` resulted in a `400 Bad Request` response:\n\nMalformedXMLThe XML you provided was not well-formed (truncated…)\n MalformedXML (client): The XML you provided was not well-formed or did not validate against our published schema - \nMalformedXMLThe XML you provided was not well-formed or did not validate against our published schematx7bd76ec0ba114f32951bb-0061d553da'\n\nGuzzleHttp\Exception\ClientException: Client error: `PUT http://moncontainer.storage.sbg.cloud.ovh.net/test.zip` resulted in a `400 Bad Request` response:\n\nMalformedXMLThe in /home/SrvWeb/BackupOVH/Proc/JSR/aws/Aws/WrappedHttpHandler.php on line 195
but if I put 'cont1/' (with slash)

$result = $s3Client->upload('cont1/', 'test.123', fopen($file_name, 'rb'), 'public-read');
an object is created in 'cont1' but named '/test.123'

What is the good way to create a container and how to [upload
a file with the correct name ?