Why "BoxReflectionCapture" dissapear when rendering?

I have a beauty effect of BoxReflectionCapture for my water surface, but it seems dissapear in video rendered?
By the way, how make the sky color in render beautiful as in viewport? my rendering skill is begin. Please help! Thanks!

Luckyly! by follow Related question, I find out problem: I forgot “Build Reflection Capture”.
Thanks forum!