Dresden elektronik deCONZ Conbee II vs. Ikea Tradfri Update

Hello. I try to update my Ikea Tradfri devices, wich i control with Conbee II. My base is a Raspberry Pi with Home Assistant Operating System. And i found this manual, but i can´t install deconz-dev, because the terminal doesn´t accept the “sudo apt install” command. So how do you update your Ikea Tradfri Hardware?