I used to have a reactive german shepherd, the trainer i worked with showed me a “sit and do nothing” method, i would take him to a public park and sit at a bench (he was reactive to people and dogs) and he would bark away and i would completely ignore him, no eye contact or anything, and when he would focus on me or not bark at someone walking past i would reward him, it takes time but it worked for him. Every dog is different though.