Problem add Shelly 1 with shelly add-on

Hello,
I have a Shelly 1 v.3 relay (firmware version 20191216-090109/v1.5.7@c30657ba) already working with his own app and with google mini.
I want to add it to my mozilla.iot too, version 0.10.0 running on docker with raspbian and Raspberry. The Shelly add-on is version 0.2.1 by tim-hellhake. When I launch new things search, my shelly 1 is not recognized. I see nothing important in the log:

2020-01-12 11:00:22.803 INFO   : About to call startPairing on ZigbeeAdapter
2020-01-12 11:00:22.807 INFO   : About to call startPairing on VirtualThingsAdapter
2020-01-12 11:00:22.811 INFO   : About to call startPairing on ShellyAdapter
2020-01-12 11:00:22.834 INFO   : Opened a new things socket
2020-01-12 11:00:22.872 INFO   : zigbee: Pairing mode started, timeout = 60
2020-01-12 11:00:22.876 INFO   : shelly: Adapter: ShellyAdapter id ShellyAdapter pairing started
2020-01-12 11:01:22.824 INFO   : Pairing timeout
2020-01-12 11:01:22.829 ERROR  : Thing was not added
2020-01-12 11:01:22.832 ERROR  : addNewThing cancelled
2020-01-12 11:01:22.840 INFO   : virtual-things: Adapter: VirtualThingsAdapter id virtual-things pairing cancelled
2020-01-12 11:01:22.844 INFO   : zigbee: Cancelling pairing mode
2020-01-12 11:01:22.848 INFO   : shelly: Adapter: ShellyAdapter id ShellyAdapter pairing cancelled

Anyone can help me? What is wrong?

Thanks
Fod.

@t1m1 is the author of that add-on, but it would probably be best to open an issue here: https://github.com/tim-hellhake/shelly-adapter

Thanks,
the issue I opened on GitHub:
https://github.com/tim-hellhake/shelly-adapter/issues/4