BluetoothLE requestMTU

I would like to send and receive 30 bytes of data.
It was confirmed that the settings were made on the device side and that 30 bytes of data were received by adjusting the MTU in nRF Connect.

The problem is that when you adjust the MTU in App Inventor as shown below, a Change Event occurs, but actual data is not received or transmitted.

device is ESP32

Is there anything wrong?
blocks (4)

I think it took a month.
I think this is when the RegisterForBytes block is called.
This was solved with the block below.
I hope this helps many developers.

Thanks for the update.

If the order is important it should be mentioned in the docs.