just add Alexa meta data to your item, but then you need to rely on the Alexa utterance and I believe Alexa is not ready for prices, therefore your item will be treated as “others” and you can only ask something like "what’s the current value of "
create a routine within Alexa and an openhab rule if you want to customize your question and the output
Btw: I’m also using tankerkoenig binding and in addition to the current gas price I’m also having the last 7 day average and 7day minimum value in separate items (using persistence & a rule) , what’s helping me to understand if current price is high or low.