Even before you passport issuance, you can book it in advance. To ensure smooth procedure, it is recommended that passport information should be input in the homepage in advance, but it is not required as an regulation. On the departure date, the counter agent will check your passport number and help you through, so please keep your passport on departure date.
However, for Guam, the Transportation Security Administration (TSA) collects information on the name, gender and date of birth of all passengers who use the U.S. route for advance security screening.
When booking for for Guam, you are required to accurately fill in the English name, sex, and date of birth on your passport within 72 hours before departure.