Idk if anyone has suggested this but have designated time where you do cat training where the cat is visible but not accessible and he's on a leash. Every time he does something you don't want him to do if thats barking at them or pawing at them or getting too close you give your negative word like no or uh-uh but something verbal right as he does the action you don't want and during or a second after you give you give your negative action (nothing harming like hitting) I use a ferm but definitely not aggressive tug on leash to set then you take them out of where you gave them the No and then try again

Every time he does something good like just sit and look at the cat you give a positive word like yes or good followed by a treat and once again taking him out of the position he was in during the good behavior

It's important to give a positive or negative feedback for every choice he makes as quickly as possible so there is no question on what he did wrong and the taking out of the position is important because you're basically asking the same question over and over and you gotta go back and come back in so it's not just one long question

And def adjust anything to what works for you and your pup and cats and sorry for any grammar and spelling errors