Technically, no. Bone broth has fat and you will break your fast. However, I drink my coffee with milk and I can lose weight on that. All depends on your goals. If you want a true fast, nothing with calories is allowed.
I do not know if this is true but according to this if you stay under 50 kcals you will remain in the fasting state. I’d also appreciate more some more info to confirm/refute the claim.