Bluetooth is built in on a RPi 4, which is what I have. The Bluetooth integration showed up a long time ago but I did not have any Bluetooth devices until I got a Govee H5074 temp/hygrometer sensor 2 days ago. No integrations popped up so I tried installing the Govee Bluetooth integration and got the same message as you, "No devices found on the network”. I tried other BT/BLE integrations I found but they did not help other than showing me that they could see the device. I was going to buy a BT dongle but decided to unplug the power and plug it back in, as a last resort. That’s when the Govee integration popped up on it’s own, showing it found a new device. I installed it and everything worked. There is a list of supported devices in the HASS Govee integration documentation at Govee Bluetooth - Home Assistant That’s my complete experience with few details left out. I hope this helps you or someone else that is experiencing the same issues.