If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

On a Linux system, curl can be used to return the issuer, authorization endpoint and token endpoint URLs by submitting a GET request to https://<the API URL of your OpenShift system>:6443/.well-known/oauth-authorization-server.

~]$ curl --request GET --url https://api.openshift.example.com:6443/.well-known/oauth-authorization-server
{
  "issuer": "https://oauth-openshift.apps.openshift.example.com",
  "authorization_endpoint": "https://oauth-openshift.apps.openshift.example.com/oauth/authorize",
  "token_endpoint": "https://oauth-openshift.apps.openshift.example.com/oauth/token",
  "scopes_supported": [
    "user:check-access",
    "user:full",
    "user:info",
    "user:list-projects",
    "user:list-scoped-projects"
  ],
  "response_types_supported": [
    "code",
    "token"
  ],
  "grant_types_supported": [
    "authorization_code",
    "implicit"
  ],
  "code_challenge_methods_supported": [
    "plain",
    "S256"
  ]
}

This could also be done in a pod running on OpenShift if the pod includes the curl CLI using the oc exec command.

~]$ oc exec pod/ose-hello-openshift-rhel8-5959c4fb77-9tdzw -n hello-openshift -- curl --insecure --request GET --url https://openshift.default.svc/.well-known/oauth-authorization-server
{
  "issuer": "https://oauth-openshift.apps.openshift.example.com",
  "authorization_endpoint": "https://oauth-openshift.apps.openshift.example.com/oauth/authorize",
  "token_endpoint": "https://oauth-openshift.apps.openshift.example.com/oauth/token",
  "scopes_supported": [
    "user:check-access",
    "user:full",
    "user:info",
    "user:list-projects",
    "user:list-scoped-projects"
  ],
  "response_types_supported": [
    "code",
    "token"
  ],
  "grant_types_supported": [
    "authorization_code",
    "implicit"
  ],
  "code_challenge_methods_supported": [
    "plain",
    "S256"
  ]
}