That was just a minimal test to see if data could be extracted cleanly (without ()) from the BLE data stream.
Did you actually try those blocks, using a Label of your choice?
Did you see data arrive in the Label?
Did it look like the data you sent?
If all those are true, my work here is done.
Questions about setting up BLE connections I leave to BLE experts.
Be aware you took a non-BLE Bluetooth sample and converted it into a BLE app.
Questions about how to feed data into a graph extension, I leave to you and the author of that graph extension.
If you want to use the native AI2 graph component, see