My rabbits were both 100% anti dog when I first got them. My dog lived here first so there was never a choice, they were going to have to get along.
Sampras was very bad, like Bramble, running away, cowering,thumping and grunting- just from the smell of her. Literally just having a big ole nope about the dog.
I worked at it slowly. I introduced the concept that the dogs smell, although alarming and unpleasant meant nothing. So it started off, I’d smell a bit like the dog, then the dogs bed would be in the room for a little while(this can be very overpowering so not always a good idea) then I took one of his teddies(that smelled like him) and wiped it over the dogs back, and replaced it in his cage.
His curiosity won out and he eventually got okay with her smell. After the smell part introducing them was the next big step, but now they he is completely confident around her!
Keep in mind to a rabbit, a dog is a predator that is a threat, so your bunny is just listening to its instincts. It takes patience