Fastest way to get client's lookvector onto server

I know this has already been done, but this doesn’t have to do with movement.

I am currently making a hitbox system for my game. It spawns a hitbox shape, does stuff to it, and accurately tells when the hitbox touches something. However, it’s spawned on the server. It also can spawn multiple at a time to prevent one static hitbox.

I want to keep the basic attacks and abilities on the server to prevent some exploiter from messing with it, but I also want accurate hitboxes. There’s also the case of attack speed affecting the speed of moves, which may affect some solutions.

Help would be appreciated.