Jalmanz but once I remove the old config and rename the sample to ost-config.php
Why would you remove the old config file?
If you are renaming the sample to ost_config then you are deleting the database connection information so osTicket redirects you to the installer because it thinks you need to install.
if you are going to do that you need to edit the renamed file with the server name, database name, database username, and database user's password.