Providing part of the design as a buyer

[dd4338]

Hello, first time buyer here on Fiverr and have a question about a project that involves me (the buyer) providing part of the design. I’d be providing some material/designs owned by my company, to be used by the seller to create another design. Is there anything I need to do to make sure that the original design (commercially owned by a company) is not reused by the seller for their own purposes? Like an NDA or something else that needs to be signed? Or is it already covered by Fiverr ToS if I purchase a commercial license for the entire project, then I own all the materials (including the parts that I provided myself) anyway and the seller isn’t able to reuse?

Thanks!