Powerhobby gnss no connection

Bought a new one on amazon. The picture on the device is gsm020 but when I first pair it to my phone through the app and it detects as gsm 018. It asks me to update firmware and I tried 3 time but it fails to upgrade. Then when I hit start the dam thing got disconnected from the phone and it hit to connect again but my phone does not see the device. Hit reset button and it does the same thing again. What is wrong?

Try with skyRC app

Read the instructions, it will not work with phone bluetooth and never try to upgrade the firmware. If you bound it to the phone you have to delete that connection.
It will only work through the app.

Does not work with phone bluetooth but without phone how can Inuse the app? And which app? The instruction says download power gnss on apple store so use it on the phone.