1. My goal is: Set some custom attributes on ESP32 over BLE.
  2. My actions are: I tried this Mongoose OS Documentation
  3. The result I see is: But only service UUID what I see is 5F6D4F53-5F43-5F33-56435F49445F
  4. My expectation & question is: I expect see service UUID 5F6D4F53-5F52-5043-5F53-56435F49445F why can’t I see this service?

Are you including the proper libraries ?
I did this quite long ago, with the former BT libraries, and it worked like a charm