Thank you for your question, Kathy.  We are reluctant to advise on the use of any chemical controls without first having an informed diagnosis of the problem, of which roses have over 30  possibilities: (https://pnwhandbooks.org/plantdisease/host-and-disease-descriptions?title=rose).

If it actually is botrytis, this diagnostic guide lists controls:  https://pnwhandbooks.org/plantdisease/host-disease/rose-rosa-spp-hybrids-botrytis-bud-twig-blight

I suggest that you submit photos, visit an Extension office with photos and plant samples, or send plant materials to the OSU Plant Clinic:  https://bpp.oregonstate.edu/how-submit-plant-materials

Good luck!