In documentation for run as service is missing mention that "jboss-eap-rhel.sh" needs the "initscripts" package. This package include "/etc/init.d/functions" file which is used by "jboss-eap-rhel.sh". So to run the the start service the file "functions" file is needed. This problem occurred only on RHEL9 because it has not the package in default build. 

On RHEL9 (not previous) before start service ("sudo service jboss-eap-rhel start", step 4) the systemctl needs to be restarted by "sudo systemctl daemon-reload" to see services which are new.