Hey,
I am flying from YXE to WAW with a stopover in YYZ and FRA. From FRA to WAW I am flying with Lufthansa but I have only the AC booking reference number. How can I check the LH booking reference? I tried classic checkmytrip but it does not work. I even tried to review my reservation by putting AC booking reference on checkmytrip but it does not work either.

Thanks!