Open the APP and allow all the permissions those the APP asks for. And tap the magnify glass icon on the right top of the APP to search the Bluetooth address. Select the right address of your kit in the list to connect.
*Note: Please connect the kit in the APP, don’t connect it in the operation system of the phone. You don’t need to input any pin to connect. And please make sure all permissions are allowed and the kit is not connected with other devices. The kit can just connect to only one device at the same time.