Yes, every device(ESP32 or ESP8266) is a hue bridge emulation like diyHue containing 1-n lights or switches. But you did not need extra hardware as with diyhue.
When i connect one device in Hue Essentials App, it runs immediately in the error i described above. I found nothing i can switch on. As i have no physical bridge, i cannot use “API explorer”, right?
I will add some debug information outputs to espalexa-lib and will post, what happens as Echo /Plus/Dot or Hue Essentials App will connect the “espalexa-bridge”, may be after next weekend.