I’ll suggest you to check the following Answer on a similar question asked 5 years ago here. Check the last answer of the moderator asd
Basically, that if you are trying to create a fresh droplet and want to retain the IP address, you have a few options. In the destroy tab, there is a rebuild option.
This “rebuilds” 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.