how to get System controlled x-amz-meta-file-ctime for an s3 object

I'm trying to get some timing how log it takes files to be uploaded an s3 bucket and would like to retrieve the x-amz-meta-file-ctime and last modified date, so I can determine how long it took for the file to be uploaded. I'm assuming the creation date is not the same, which it appears that they are not. When I tried to access the metadata using list_objects_v2 or head_object, the metadata is always empty, even though when I check the files on console I can see the metadata. Is there a boto3 method I can use to get the system controlled metadata?