EAP 8.0 "Installation Guide" Section 7.1 "Running JBoss EAP as a service on RHEL"
https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/8.0/html-single/red_hat_jboss_enterprise_application_platform_installation_methods/index#assembly_running-jboss-eap-as-a-service-on-RHEL-and-microsoft_default

The documented steps do not work as is on RHEL 9.
The "For Red Hat Enterprise Linux 9" section from the corresponding EAP 7.4 docs (EAP 7.4 "Installation Guide" section 2.4) is missing and needs to be copied over.