Last weekend I could play with the ESP32 board to implement BLE transport for FIDO2 WebAuthN protocol. The great BLE library for Arduino [https://github.com/nkolban/ESP32_BLE_Arduino] and tutorials [https://circuitdigest.com/microcontroller-projects/esp32-ble-server-how-to-use-gatt-services-for-battery-level-indication] helped me a lot. Now my developer board advertises itself as FIDO2 Authenticator and provides four required endpoints to communicate. Google Chrome is able to detect the device and tries to connect to it which I consider as a great success for the weekend project. However, the endpoints just do nothing at the moment and authentication fails with an error.