Fitbit integration issue

Is anyone using it ?
I followed the instructions at :

I added the sensor exactly as shown. After I restarted HAOS, I never got the notification to setup Fitbit, though.
What am I missing ?

My HAOS is setup with SSL and a .localdomain self-signed certificate. It’s not exposed directly to the Internet. I access it remotely with a VPN when outside of home.
The integration documentation says this configuration is OK.

So, how can I make the notification appear ?