Speed controlled by kinni using Zwift

Hi friends! I’m a new user of Zwift and it’s a great apo, but as Somerset of you already told, we only need Zwif to automatocally control the speed of treadmill.
Well it seems that Kinni app can conect to zwift and control it but I am not able to connect them correctly. I know I have to connect kinni to treadmill and then zwift to kinni… But then? I try to begin a training session with zwift and nothing happens, speed is not controlled

Can anybody help me please? Thanl you!!