In Germany fuel processes must be reported to the anti trust authority (Bundeskartellamt) the data is than published to providers of apps and websites. Unfortunately there isn't a free public data stream from them.

List of authorized places using the data: https://www.bundeskartellamt.de/DE/Aufgaben/Markttransparenz...

One of those vendors publishes it as creative commons data set, though. Including historic data. https://creativecommons.tankerkoenig.de/