I also booked through an OTA. I've received PNR and ticket numbers. With them, I have no problem to access my booking using this link. It works for seat reservation and special meals. Interestingly, I was able to reserve seats with the OTA (Gotogate) free of charge and they made it into the booking. But I can't enter my frequent flyer information nor passport details. I wait for online check-in if available or as last resort at the airport of CDG.