If you've reached this page by following a URL attached to a WebDAV resource lock, then the client imposing the lock has not specified a custom/personalised lock contact URL. This means that there is unfortunately no way to contact the owning user by simply inspecting the lock.
If you've reached this page by exploring the WebDAV client library repository, this page is the default LOCK method contact URL. You can override it when creating a new WebDAV client instance.