App Inventor, Microbit and BLE UART

I've been trying to use UART to send messages from APP Inventor to Microbit v2 and back using tutorial "App Inventor, Micro:bit and UART - November, 2021" however I am stuck trying to detect the microbit from the App Inventor, which should be the first step before being able to send the messages. I am including the code for App Inventor as well as the code I'm using for microbit side. Would appreciate any help.
BleApp.aia (290.4 KB)

Hi Leonard,
I have alerted our IoT expert in the Team to take a look at your question. In the meantime you may wish to check our new IoT curriculum to see how some of these issues are resolved.
http://appinventor.mit.edu/explore/ai2/IoT_unit

Hi Leonard, A few things might prevent Bluetooth detection and connection. We have new Bluetooth extensions that work smoothly, and every tutorial from fall 2022 is current.

For your UART-based project, I would start by loading the Microbit and App Inventor templates located in our Project 2 tutorials, and then modify to your needs. The templates have a nice event-based structure for sending data.

Here are the files:

Setting up the Microbit (this hex code for Microbit will adjust the settings in the MakeCode IDE)

Setting up App Inventor (this contains the latest UART extensions)

Many thanks Selim and Robert for your help.
I will give it a try.

(added to FAQ)