Local kafka as event source

I’m trying to build a local development environment in order to make my local tests.
I need to use kafka as event-source.
I’ve deployed a self-managed cluster into my local environment using docker.

An issue is running in my mind according to documentacion, I need to provide authentication.
Here there’s no problem, the issue is which kind of values documentation is required I provide, AWS secrets.

What do those kind of secret, AWS secrets, have to do with my self-managed self-deployed kafka cluster?
How could I provide my kafka cluster a local event source?

I mean, I thought I only need to provide bootstrap servers, consumer group and topic… Something like knative serverless documentation says.