Limiting frame rate (fps) in my game isn't working. (dev. for WebGL)

I'm working on a game for WebGL, and my MVP is iPad 4. So I need to limit the frame rate to a constant 30fps. I've tried the Unity way: https://docs.unity3d.com/ScriptReference/Application-targetFrameRate.html Changed it, and the frame rate stayed unchanged. Is there another way to do this? Or is there more to changing it than what is says in the link? Thank you!