I agree with other users saying neem oil. Just be careful, its oily, stinks when sprayed and it is technically a pesticide (even though its natural)
Also yes to other users suggesting cut back to root/above node. All dead/brown stuff is exactly that. Dead. If you really like a certain leaf you can trim brown spots off, but if the cause is underlying like bugs or nutrients that hasn’t been fixed it will continue to brown
Good luck! Monstera are tough, she’ll be fine soon
I agree with other users recommending Mint