How to breathe when doing strength training?

Hi all, my first thread here! 👋🏽

Been doing FB workouts on and off for 8-9 months and despite having fallen off the wagon about 10000 times, I've really started seeing improvements!

I know that K&D always say "Don't hold your breath" and "Keep your lungs open", but I wonder how exactly should you breathe when doing strength training, especially lifting-related exercises? (eg. deadlifts, weighted squats, bicep curls)

I tried searching online, but I got many conflicting answers and I'm not sure how to implement those. Any difference between recommended breathing methods for pro athletes vs for beginners?

Thanks!

(I've searched existing threads but could not find this info, apologies if this has been discussed before.)