In order to add a passport number onto your Green Passport (Tav Yarok) for travel and other purposes, you must first have a Tav Yarok. This will show the ID number by which you were tested, which will be your 77 number or Kupat Cholim number.
For Meuhedet members, you can email your local branch (e.g. email@example.com/ firstname.lastname@example.org/ email@example.com etc.). Write a brief request including your name, Meuhdet number and the passport number you want added. Attach a copy of your Tav Yarok and your passport. They will forward your request to the Chamal who will then send Meuhedet a new, updated Green Passport for you.
For members of all other Kupot Cholim, please contact your local branch for information on how to do this.