I would hope the Pacific Command does not need to rely on the Hawaii government to communicate with its commander in chief.
In any case, given the adversary, launch on warning is not necessary (except to shoot down the incoming). The President would have ample time to verify the source of the attack and survey the damage before ordering the merciless counterattack.
A more interesting case to consider is the proper response if Kim were to launch a missile that is successfully intercepted before reaching Hawaii.
This is the thought that I had. I don’ think that was the case here, but if such an event occurred I am not sure that we would be told,