There are several JDK options available when installing FlexDeploy. The main requirement is that the version of Java used is version 11 or 17. if your Linux distribution includes a build of OpenJDK 11 or 17, you can use that version.
Amazon Corretto - Amazon's build of OpenJDK with security updates https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html
OpenJDK - https://adoptopenjdk.net/releases.html
Oracle JDK - Oracle's build for those who are licensed https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html