Occlusion culling world generation runtime

I am making a voxel-based game where a terain gets generated. For each world, millions of blocks are generated. This, obviously, is a real pain in the backside for any computer. To reduce lag severely, I need to add occlusion culling.

The problem is you have to bake a area in the sceneview for the occlusion culling to work in that specified area. So, how would I use occlusion culling in a game where the world gets generated at runtime while a world gets generated?