I would use RenderStepped, but it requires a LocalScript, and I don't wanna use that.
Short answer is wait()
, Long answer is don't do it.
there is an article on the blog that talks about the usage of wait() in many games and how this is unnecessary and creates a huge amount of unneeded lag. I would highly recommend you read it before doing anything.
You could try:
game:GetService("RunService").Heartbeat:wait()