How do I Live Test Apps in MIT App Inventor?

Not connect live testine in app
On test in companion version 2.60

You haven't provided enough information for us to really help you. Could you tell us more about your environment? What browser are you using on the computer? What device are you trying to connect with? Are they on the same network or different networks? Do you receive a specific error message? Are you trying to connect with Use Legacy checked or not?

Once we have more information we might be able to give you specific advice.