I cant found my shadow 
I tried and I am still sucks.
What am I missing?
Answer by myself.
Remember to add ‘shadows’ props in canvas 
There are something diff between react-three and normal three.js
these are just shortcuts, there are no differences between fiber and three. if three docs say that the renderer needs this:
gl.shadowMap.enabled = true
gl.shadowMap.type = THREE.PCFSoftShadowMap
then the same holds true for fiber. you can access the renderer everywhere and just set it up. you rarely see that because the <Canvas> component has a couple of props that help you set up threejs quicker, they’re all explained here: React Three Fiber Documentation