Diagnosing invalid client ID in Authorize URLs

While following along https://developer.okta.com/docs/guides/add-an-external-idp/oktatookta/create-authz-url/, I noticed that when I used the wrong client ID, I (naturally) got “Bad request” responses from Okta. However, it took me quite a long time to realize that the client ID was the culprit.

Is there some way in Okta to diagnose this kind of errors? I’ve noticed that for invalid redirect URIs, the bad request error page contains a corresponding error message, but for client IDs it doesn’t. There’s also apparently no entry in the system log.