I need to set X-Delete-At or X-Delete-After for already existing Object in storage. I tried to do it using $openstack->objectStoreV1()
->getContainer($containerName)
->getObject($fileName)->mergeMetadata([
'X-Delete-After' => "10",
]);

AND

I used:
$openstack->objectStoreV1() ->getContainer($containerName) ->getObject($fileName) ->mergeMetadata([ 'deleteAfter' => '100', ]);

But it sets X-Object-Meta-deleteAfter param, and not the X-Delete-After metadata value.

So my question is how to set them?

Additionaly
Official docs https://developer.openstack.org/api-ref/object-store/?expanded=get-object-content-and-metadata-detail
says that "In addition to the custom metadata (like X-Object-Meta-name), you can update the Content-Type, Content-Encoding, Content-Disposition, and X-Delete-At system metadata items. However you cannot update other system metadata, such as Content-Length or Last-Modified."

But I cant find this ability in php-opencloud.