Is it necessary to show samples when applying for a patent?

No samples are required, and applications in kind are not accepted. The attached drawings are not strict. As long as the innovative parts are drawn in detail, other parts can be simplified. You can find an agent. First of all, you should pay attention to whether it is a nationally recognized institution. If not, you'd better not look for it. Don't forget to sign an agreement before the formal agency, that is, before you send your information to the agency. One of them is a confidentiality agreement, which is to keep your plan secret. If they don't sign an agreement with you and ask you to provide information, they are lying to you.