What is the purpose of the REST API listen port in Qlik Sense?

The purpose of the REST API listen port in Qlik Sense is specifically designed for integration with external systems, which often involves handling authentication requests from those external systems looking to access Qlik Sense resources. When using an external authentication module, the application communicates through the REST API listen port to manage the traffic associated with users trying to authenticate. This enables Qlik Sense to seamlessly integrate with various identity providers or custom authentication systems.

In the context of the other options, while managing user sessions and handling data connections are important functionalities within Qlik Sense, they do not specifically pertain to the REST API listen port's role. The port does indeed interact with authentication requests, but it does not manage sessions or data connections directly; its main focus is facilitating communication between Qlik Sense and external authentication providers.