Pacifiers should be taken away by 15 months at the latest. If you wait longer than that you'll have a harder time getting your toddler to give up their pacifier and have to deal with tantrums over the pacifier being gone.
Take it away as soon as possible or better yet don't give one to them.
The toddler can't miss the pacifier if they didn't have one in the first place. But then again they'd be sucking their thumb and that's harder for them to give up and you can't take their thumb away. lol