Since Opodo uses Amadeus as their booking system (like LH), you can also try accessing your reservation via www.checkmytrip.com using the six-character booking reference you got from Opodo. If your e-ticket has been issued already, it will show on CMT. If it does not, it might be time to give Opodo a call.

In any case, if your FTL number is in your booking, you should have no problem checking in with your FTL card.