The plugin notes stated that EM will extract the client_id from the JWT.
Sample Log :
2019-12-11T22:00:50.582Z plugin:extauth Found JWK
2019-12-11T22:00:50.590Z plugin:extauth JWT Expiry enabled
2019-12-11T22:00:50.631Z plugin:extauth JWT is valid
2019-12-11T22:00:50.632Z plugin:oauth missing_authorization
2019-12-11T22:00:50.632Z plugin:oauth auth failure 401 missing_authorization Missing Authorization header { 'user-agent': 'PostmanRuntime/7.19.0',