You work in the Neo environment and you need to use logs, please use this tutorial to help you get started with the SAP Application Logging service. This is a quick tutorial that will help you learn how to create loggers and log messages, and how to view your logs.
This tutorial uses the hello-world sample available with the SDK that you can install from the SAP Development tools. Furthermore, I assume you already have a customer account and are familiar with the SAP BTP cockpit as an administrator in the Neo environment. All the other steps in the tutorial are straightforward.