Thanks lbernstone for your reply.
In contrast with the TSL devices of your link, my ESP32 is visible in the devices discovery list and can be paired with Windows.

The problem comes when trying to open the relevant COM port. The serial terminal sends a "timeout connecting to COMx".
I understand that ...

A project of mines invloves sending data from a sensor to Windows via a serial port over bluetooth.
My first test was to compile and upload the " SerialToSerialBT.ino " sketch example:
1) It compiles and upload fine;
2) Discovering the ESP32 as a bluetooth device and pairing it from Windows works ...