Do I need Carbon Console admin credentials to monitor WSO2?
No. Nodinite needs JMX remote access to the WSO2 JVM, not Carbon Console credentials. The JMX Monitoring Agent never signs in to the Carbon management console or calls the WSO2 Management API. Its Spring Boot JMX Gateway connects to the JMX remote port that you configure per WSO2 server as an Application Host (address and port, Configuration).
What You Configure Instead
Give each WSO2 JVM a JMX remote port with the standard JVM options in Enable JMX Remote Monitoring, and open that port from the Agent Server only (JMX firewall section).
Where WSO2 Credentials Come In
WSO2 Enterprise Integrator 6.x also starts its own Carbon JMX server (default ports 9999 and 11111 in carbon.xml). According to the WSO2 Carbon administration guide, remote clients of that JMX server sign in with a WSO2 user in the admin role. You don't need that built-in JMX server for Nodinite; the standard JVM JMX port described above is enough.
If your security policy requires authentication on the JMX port, turn on jmxremote.authenticate with a password file on the WSO2 JVM, and use the same credentials in the Spring Boot JMX Gateway configuration, as described in Enable JMX Remote Monitoring.
Micro Integrator
The same applies to WSO2 Micro Integrator: the JMX Monitoring Agent doesn't use the Management API or its credentials in deployment.toml; it needs a JMX remote port on the Micro Integrator JVM.