Certified GKH Gardening Expert
Do a search within your area for local rabbit farmers or browse want adds for rabbit manure. You can also check with your local garden centers as many times they sell packaged rabbit manure. Farmers markets may also be a good place to find the manure.
In the meantime, here is an article that you may find helpful: https://www.gardeningknowhow.com/composting/manures/rabbit-manure-compost.htm
Check with your local County Extension office or look up 4H Clubs in your area. Usually some of the kids in 4H have rabbits as their project. They will usually let you have all you want for your gardens or rose beds. Also you could do a search for the American Rabbit Breeders Association and see if any are in your area. Another place would be if you have a local livestock feed store, they usually have folks that buy rabbit pellets to feed their rabbits. You could call them and see if they have any to spare for your needs.