First, type the Konami code into your terminal, then...
Create a user, then create a password for the user...
oc create user doug
htpasswd -c -B -b /tmp/doughtpass doug s00persecret
Create an ident yaml...
$ cat ident.yml
apiVersion: config.openshift.io/v1
kind: OAuth
metadata:
name: cluster
spec:
identityProviders:
- name: dougprovider
mappingMethod: claim
type: HTPasswd
htpasswd:
fileData:
name: htpass-secret
$ oc apply -f ident.yml
Then you can login and check that you're logged in as that user...
$ oc login -u doug
$ oc whoami