Yes. The Five Behaviors Certification requires access to the Five Behaviors Facilitation Kit. If your company has already licensed a kit, you don't necessarily need to buy another one, but you will need access to the kit in order to complete the course materials.
This is because the credential being earned is that of "Certified Practitioner". As part of the course, you will learn not only about the Five Behaviors model, but also how to use the kit materials.