GNU/Linux Oracle 9 Enabling Dnf CRB Repo
This tutorial shows you step-by-step How to Add Code Ready Builder Dnf Repository on Oracle Enterprise 9 GNU/Linux – Step by step Tutorial.
And CRB Repo for Oracle Linux 9 repository provides most of the Developer Tools.

1. Terminal QuickStart
How to QuickStart with Command Line on Oracle Linux 9
2. Enabling CRB Repo
Finally, to Add CRB Dnf Repository
Install the required Tool with:sudo dnf install dnf-plugins-core
And then play:sudo dnf config-manager --enable ol9_codeready_builder