Never tell them what you're currently on, just what you want.
I always have an answer that is locked and loaded 20-40% more than what I’m actually making and generally ask for about 20% more than that. I’ve bumped my pay over $100k in 5 years doing that. Keep in mind I also refuse to work for FAANG-y companies.
"I'm pretty happy where I am, but if you can offer me at least $X/year, I'm interested."
I imagine most recruiters would say they can't match that. Some would scold me for just looking for a paycheck, as if that's not what literally everybody is doing.