Light building cannot be performed at runtime.
It takes a significant amount of time and is handled in part by an external application.
You could make your scene entirely dynamic, in which case there would be no lighting to build.
Distance field lighting is surprisingly performant and requires no baking, you should look there.
Depending on the number of lights you will begin to run into performance issues.
Figuring out what the limits are on lighting will be very specific to your game, so it’s a matter of trial and error to see how much lighting can be done with distance field lighting.