Well, first you need to know why your dog is barking. There are many reasons for barking. I don’t think barking is modified in an easy simple way. It takes work. The first thing I do is start by reinforcing quiet. I may only get the brief interval when the dog draws a breath, but I click and treat that. I do that in a controlled environment and gradually increase the duration of quiet required for the click. I also acknowledge the reason the dog is barking. I pick up my dog, stand at the window and say “Yes, I see the person/dog/plastic bag blowing down the street. Good boy!” I train a classically conditioned response to their name and use the name as a focus cue. I find triggers and work on bumping thresholds. And what I do when depends on what is making the dog bark in the first place.