When you use your own nameservers you will want to create glue records at the registry. This will make sure that the registry sends the visitors to the right servers.
A glue record is commonly also called Host Object, nameserver object or glue host.
When your domainname is in the Openprovider system and has no glue-records yet, you can add this glue-record on the following page:
It will then appear here:
If you do not create a nameserver object in our control panel you risk configuration issues. The nameserver object will override any other settings you send with domain update commands, preventing you from taking down all your domains by making a mistake in your IP address.