By default, it follows the fps of the graphics settings.
engine.runRenderLoop(() => {
scene().render();
});
So instead of fps in the engine, in the form
let customFPS = 60 ;//120 or 250
let renderInterval = setInterval(() => scene.render(), 1000/customFPS);
engine.runRenderLoop(() => {});
If you use it, you can use it in whatever form you want.