How to read out (german) smart meter Landis Gyr E320

Hi folks,

I’m afraid this questions is very german specific since each country seems to have its own power meters. But anyways.
I am already using a Landis+Gyr E320 power meter which I already read out using volkszähler. This is quite nice, but it is only reading. To make my house a bit more intelligent I just started with Home Assistant. I already added some stuff using the GUI, but when it comes to integration of a smart meter (especially the Landis+Gyr ones), it seems to work only by configuring YAML files.
At the moment I see two ways to read out the power meter:
a) using volkszähler delivering the values
b) reading it out directly

I already started trying around with option a), nevertheless it would be more elegant to go with b) in the end.

For a) I found Volkszaehler - Home Assistant
I edited configuration.yaml accordingly and made the values coming out of volkszähler via REST API (confirmed it using a browser). How can I now access the sensor and let it output to the GUI? I found it nowhere. How can I debug?

For b): Is there anyone who knows how to read out SML power meters directly with Home Assistant? That would save one Pi which is running volkszähler at the moment.

Curious for your answers,

thanks & cheers
Marco