Debian 10 (Buster) was released in July 2019, and you may be looking to upgrade from Debian 9 (Stretch). The end of Debian Long Term Support for Debian 10 is not yet announced. Debian 9 will receive Long Term Support through June 2022.
While Hostwinds offers the ability to reinstall your VPS operating system, this would erase any data on the server. Instead, you can take a precautionary snapshot of the VPS if you are not using Hostwinds cloud backups. With a backup in hand, you can proceed with the upgrade.
Configure Apt Sources
Start by backing up the file /etc/apt/sources.list: