Connect with my phone via blele,but can't communication with my inventor app

I have actually use this inventor tool to create some apps about bluetooth followed the steps of so many tutorials. Even though it can be able to connect with my app,but it can't communicate with my board(arduino nano 33 ble sense).I don't know why?

1.The tutorial says that I need to first paired the phone with the board via ble and then use the app(created through BluetoothClient) to communicate with my board.But I can't paired my phone with my board.

2.Therefore I choose the bluetoothClientLE to create the app, and the app is actually connect with my board,but the board can't listen to any services or characteristics that the app made. Or to say both the board and the app can't recieve the data that the paired one sends.

1)The interesting thing is that if I use the nRF Connnect app to connect with the board,it is ok and I can see the services and characteristics .And they can communicate with each other perfectly.
2)If I use the app created by app inventor and the board can't recieve the same service and characteristics send by the app.

The second problem has confused me a few days, I just don't know what to do. Do I need to change a phone or something?My phone is actually a normal android phone.
Can anyone help?

Hello Jerrick

It's relatively basic but first and foremost ensure that all devices in your setup are BLE compatible.

Assuming they are, you need to ensure that the Script (Arduino Sketch) for the Nano and the code in the App are singing the same song.

We need to know what communication you are trying to make (what data?). How about posting your App Inventor Blocks (right mouse menu in the workspace, "Download Blocks as Image"), and your Script (as a .txt file).

An exported .aia file would also help determine the version of the BLE extension in use.

On my website:

The latest MIT BLE extension is