Enter it on the AA website for your booking’s passenger info as AA owns the booking and it will be stored associated with the PNR. Same thing with KTN, etc.

JAL doesn’t seem to allow you to change anything except seat selection and meal choice for a booking that they don’t own and even if they own it, you cannot do some things online. Have to call customer service who can’t speak English properly most of the time.

Their app and online software is the worst I have seen for any major airline. Embarrassing for a developed country. My one and only experience so far dealing with these things (on a paid J) has been terrible enough to make it the last time I will fly JAL.