If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.
The oc login command is used to log into OpenShift.
oc login oc.example.com:8443
You should be prompted to provide your username . . .
Authentication required for https://oc.example.com:8443 (openshift) Username:
. . . and password.
Or, a token can be used, so that you don't need to authenticate with a username and password. Obviously, replace "abc123" with the actual token.
oc login oc.example.com:8443 --token=abc123
If you are authenticated, something like this should be displayed.
Login successful. You have access to 193 projects, the list has been suppressed. You can list all projects with 'oc projects' Using project "default". Welcome! See 'oc help' to get started.