Ingolstadt apparently. I couldn’t find the exact one, but there appears to be only 2 burger kings in the city, and I suspect it’s this one (warning: google streetview)

God what a beautiful city Ingolstadt looks like from above though, with the Danube flowing through it, and the old city having an actual green belt around it

I walked past there this summer, that one is still a burger king.

do you know where it is then, I typed in “Burger, ingolstadt” and got mostly nonsense results

So, I'm still googling it, it seems the one south of Ingolstadt was from the same owner, but this one had just re-opened last summer (I'm assuming new management) after being closed for a while. Still haven't found the "Burger" one though.