The “rebuilds” option on your droplet based on the selected image. It’s important to note that this will destroy all of your data on the droplet, but it will retain the same IP address.
If you need to retain the data, you can take a snapshot and destroy the old droplet to release the IP address. Then create a new droplet based on the snapshot using the same hostname as the original droplet. The system will try and retain the IP address for you, but it is not guaranteed. The sooner you launch the new droplet, the more likely it is to work.