How do I black balance a BM camera?

Hey folks,

as my title says. I don't know how to black balance my Blackmagic cameras other than either in post or with an ATEM switcher.

I do not always have a laptop or an ATEM with me and I can see sometimes a little color shift in darker areas of the shot on a bigger monitor.

I know from other camera manufacturers cameras that they do have an option to do an automatic blackbalance in camera.

Is there an option on BM cameras aswell that I'm missing?

Thanks