How do you install JAVA 8 on a new server?

I would like to start by mentioning that I am very new to Linux. I have been wanting to give MineOS a try for a while now and re-purposed an old Dell Optiplex to do it. I want to run multiple servers on it and haven’t had a problem getting vanilla servers to run with the newer versions of Minecraft. The problem that I am having is with the older versions, primarily with the forage versions. I have used the two forum posts tagged at the bottom to install JAVA 17 without issue so that I could run a 1.18 server. The problem that I am having is with JAVA 8 so that I can run forage 1.12.2 servers. Any help would be much appreciated.

Upgrading to Java 16 from the MineOS Turnkey ISO - Command-Line - MineOS Forum

Multiple Versions of Java on MineOS - Web-UI - MineOS Forum