1. First, you need to determine the source and authenticity of the Buddha's head. Make sure it is genuine and purchased from a reliable place.
2. If you suspect that the Buddha's head is fake, you can try to contact the seller or manufacturer to find out whether they provide steel seal service or whether they can provide you with other documents to prove the authenticity of the Buddha's head.
If it is confirmed that the Buddha's head is genuine, but there is no steel seal, its authenticity can be proved by other means. For example, you can consider using information such as the material, technology and brand of jewelry to prove it.
If you are not sure about the authenticity of the Buddha's head, or want more professional advice, you can consult a professional jewelry appraisal agency or professionals, who can provide you with more detailed advice and guidance.
In short, if there is no steel seal on the Buddha's head, you should first confirm its authenticity and source, and then take appropriate measures to prove its authenticity. If you are not sure about the authenticity, or want more professional advice, you can consult a professional or jewelry appraisal agency.