It should work wherever
boundary=low_emission_zone is used in OpenStreetMap (I just checked - it works for Munich as well as London). However, using
this overpass turbo query, it seems that there are many countries with zero instances:
I don't know why that is!
Even when shown it might be difficult to spot the dashed green line in OsmAnd if you didn't already know roughly where it should be. E.g. here's the North-West corner of Munich's LEZ: