To add travel documents for your travelers like passports, identity cards or driver's licenses, click on "Travelers Overview". Then select the relevant traveler.
Passport details make the booking process a lot easier, esp. for frequent flyers. Some airlines also need those details for flights within the EU.
Travel documents you can provide:
✔ Passport
✔ Identity card
✔ Driver's license
Not logged in?
Follow that link: https://my.comtravo.com/travelers/list.