Gift card question re: Royal Caribbean cruise line

[Susie]

My brother and SIL are going on a cruise on Royal Caribbean in the spring, so I was thinking of getting them a GC to the cruise line for Christmas, to put toward a drinks package, or spa services or whatever on the ship.  Useful for them, easy to shop for, win-win.

It seems like RC is really restrictive in what you can use GCs on though.  Like here (https://www.royalcaribbeanincentives.com/royal-caribbean-gift-card-program/) it seems like you can only use GCs on the fare itself, and not on shipboard credit/extras:  7.  Certificate may not be used to obtain onboard credit or to settle any shipboard charges.

Is there a way to accomplish this that I am missing?  Can you use it to buy packages ahead of time?  Or is RC just difficult to use GCs, and I should come up with a different idea?

I haven't cruised in many years, and never on RC, so any advice is appreciated.

[origami]

I would call to confirm, but on the gift card page it says, “Use them towards the purchase of a cruise or for onboard credit toward the spa, gift shop, bar, specialty restaurants and more.”

www.royalcaribbeancertificates.com/

That would be really dumb not to be able to use it for anything onboard