Apple's signature can be divided into * * * signature, independent signature, super signature and TF signature. * * * Although the signature is cheap, it is only a few hundred dollars. Answer: But it is easy to lose the signature. Of course, legal person signatures are also unstable, such as independent signatures. Although the price is a little expensive at one or two thousand, it is extremely stable. (Kaka) Sign to launch his account, and the signature that can't be stabilized. Professional platforms have a refund mechanism, so that the rights and interests of customers can also be guaranteed.