After Grid infrastructure 19c has been installed, we turn to install database software.
[oracle@primary01 ~]$ cd $ORACLE_HOME
[oracle@primary01 db_1]$ ./runInstaller
Since we are creating a cluster database system, we Set Up Software Only here, then create a RAC database thereafter.
Installing software-only is pretty fast, but creating a 19c RAC database is not, it may take a long time to complete.