Please be sure to read this first: Please read this, before you start!
To install the latest packages, you should run apt dist-upgrade.
However, you still need to upgrade to version 22.04.
Based on your current level of experience, I wouldn’t recommend doing this upgrade on your own. Just because Hestia runs for free on the Oracle stack doesn’t mean it’s a good idea — unless you have solid system administration knowledge, it can easily go wrong.