Hc08 bluetooth module + sensor

Hello everyone!
I am new and looking for help in using the hc08 bluetooth module.
The project consists in reading the data of a sensor on an app created on Mit app Inventor2. Once all the components have been connected (including the Bluetooth module), when I go to select on the app of my phone (Iphone) the connection with the Modoulo HC08 gives me an error and therefore it is impossible for me to use it.
The Bluetooth module has been connected correctly and the light is flashing.
Thanks to anyone who will be able to help me.

Cross-posting on Italian section : Funzionamento modulo bluetooth hc08 ble + sensore

This thread will be closed, continue on Italian.

Guglielmo