The Open-AudIT installer doesn't cater for Oracle Linux. To get Open-AudIT installed and running, follow the below.
Install Open-AudIT as per normal.
You will not have the required php-mbstring package and you will need to allow access to MariaDB and the OMKD daemon from the HTTPD daemon.
Disable the firewall. You might also allow specific rules, that is left to the user.
To allow MySQL access, run the below on the command line.
To allow outbound proxy requests (from httpd -> omkd)
Install the php-mbstring package and restart Apache.
name=Oracle Linux $releasever Optional Latest ($basearch)