Service is provided by people. You, for example, discover a problem with OpenAI's system that you integrate with and the only way you can address it is to employ the services of the people who work for OpenAI. While that is an example of a macroservice (or what we usually just call a service), it playing out in the macro economy, microservice is the same concept except applied in the micro scale.

But you checking out the code and debugging it means that you are providing the service. Where, exactly, do you find the service (micro or otherwise) boundary in this case?

Or are you just struggling to say that your service utilizes multiple applications?