Hi @Fabricio_Araujo, welcome to the forum 
A quick note: there is a bug in the Windows Service installer for the Agent with 2.1.0.5 stable, which prevents it from starting. You can use the Release: 2.1.2.1 (Beta) 2025-10-03 as it is fixed there.
I have recently updated the documentation to clarify that:
The agent only does outbound websocket connections, which works well with most firewalls. The initial registration is for https://api.duplicati.com and after that there is just a single websocket connection on https://agent.api.duplicati.com