If you do not use the option to automatically renew a domain name then they will be deleted on the expiration date in Openprovider, causing the domain name to become available for registration or entering quarantine.
You can also choose to cancel a domain name before the expiration date in Openprovider. To do so you can navigate to the details of the domain name through your domain name management and click Remove domain name.
Some domains can be reactivated after you have deleted them or accidentally had them expire. In the queue for reactivations you can see all domain names that you can reactivate. Please note that some TLDs charge money to reactivate a domain name, we will have to forward the costs for this reactivation to you.
To reduce the costs of reactivation we have implemented a functionality called 'Soft Quarantine', you can read all about it in it's own article here.