I need some clarification over this card correct use

the Command Shuttle card says: - Use a special ability () on one of your characters.

well some friends are telling me that this refers only to special abilities on character cards like darth vader SoR10 which make no sense for me

they are changing the "on one of your characters" with "of one of your characters"

i think that you can use any special ability on one of your characters. like force speed SoR 55 - special ability Take up to 2 additional actions.

so i can use the special ability of command shuttle to give my emperor 2 actions like using the force speed special ability.

Who's right them or me? thanks in advance:)

Them. The special ability on an upgrade attached to one of your characters is not "on" that character. It's "on" the upgrade.

only works on special abilities printed on the character cards themselves.

the card that works on upgrades is cunning