I have snippet which create script to run in post configuration, I want to add satellite user in that script

i.e
cat > /root/join_realm.sh << EOF

!/bin/bash

realm join --user=SATELLITE-USER
--computer-ou=OU=OU_LINUX-GENERAL,OU=OU_Servers,DC=XXXX-,DC=ITSA,DC=YYYY,DC=YYYY zzz.zzz.zzz.zzzz --verbose

I tried to look in A.3. Satellite Specific Functions and Variables all found @host /os related variables and functions

Regards