1. If it is signed by the buyer, the buyer's receipt certificate can be provided. As long as it is the buyer's signature, it can prove that it is the buyer's signature. According to the dispute settlement rules, Taobao will not support the buyer to claim that the goods are lost (it will ask the buyer to provide a written red stamp certificate issued by the courier company to confirm the loss of the goods before signing for it);
2. If it's not signed by the buyer himself, and Xiao Er thinks it can't be regarded as signed by the buyer himself. Taobao will ask you to upload a written red stamp certificate from the courier company. To prove that the signature is authorized by the buyer. You should ask for this certificate from your local delivery courier company, not from the buyer's local courier site. The other party can completely ignore you, because the goods have been signed for.
In terms of methods, you can directly find your local courier company to explain the problem and then tell your solution. First, the courier company steals and asks them for compensation; Second, if you are not a thief of the courier company, please issue a receipt certificate. This certificate proves that all courier companies are very familiar with the format and requirements required by Taobao.