Okta Article: Find your application credentials.
The Client ID and Client Secret will be generated after you create an OIDC Web App as mentioned in following: Okta Help Center (Lightning)
Create OIDC app integrations | Okta
The Client ID and Client Secret will be generated after you create an OIDC Web App as mentioned in following: Okta Help Center (Lightning)
Create OIDC app integrations | Okta