Sensor tankerkoenig in lovelace

Hi all,
since a few days I discovered the integration tankerkoenig for me.
I would like to have a card in Lovelace which shows all gas stations retrieved from the integration. So reflecting closed and newly opened stations without having to add / delete them manually as sensors. How could I do this? I started in dev-templating with:

{% for state in states('sensor.tankerkoenig') -%}
  {{ }}{{state.state_with_unit}}
{%- endfor %}

Which is obviously no good since it returns nothing.
Tankerkoenig gives me roughly 20 stations at the moment, multiplying when you want to have not only Diesel but other fuels as well.
I have to admit that my scripting capabilities in HA are still quite limited and I would also want to understand how I could filter the stations so to show - for example - only the stations which are at average price or below of all stations.

Thanks in advance!