So, as per my understanding, that UUID is generated by iOS based on some hardware property of the BLE device (e.g. MAC address).
Regarding this:
Of course you can write your own code, which can generate similarly guid and create QR code with it, then you can add such guid in advertising packet or do whatever you want with it.
...is there any known code-example for ESP32 that could help me change that original UUID/GUID that iOS generates, to a custom one generated by me?
Thanks,
A.