Home Assistant integration: how to?


I discovered Home Assistant integration last week and it seems very powerful!
However, I find it quite difficult to go beyond basics stuff.

Basic: integrate existing ecosystem that is already on the network with their hub (philips hue). Very straight forward.
Less basic: install external devices (Zigbee stick) that will allow other devices to communicate with the system. Umbrel seems closed and my stick is not recognized… Also, I have trouble doing automations (saving them does work…).

If someone has tips, do not hesitate to share here!