Lufthansa Not Asking for Passport Information During/After Booking.. Is It Normal?

Hello, just as the title says, I booked a flight with Lufthansa from CAI to FRA for the 25th but it did not ask me for any passport information during any stage of the booking. Is this normal or did I miss something?

Additionally, if they ask for this information during the check-in, how would I go about it if I decided to check in at the airport instead of using their online check-in service? In other words, will they send me an email to check in before the flight, and should I just ignore it since I will be doing that at the airport?

Thanks in advance! :)