Taobao sellers cannot provide authorization and invoices.

1. First of all, you can communicate with the merchants and ask them why they don't provide the power of attorney to ensure polite and rational communication with the merchants.

2. Secondly, understand whether relevant laws and regulations require merchants to provide power of attorney.

Finally, if the merchant refuses to provide the power of attorney, he can seek legal aid. If the merchant's behavior involves fraud, infringement or other illegal acts, he can complain or report to the relevant regulatory agencies or consumer protection organizations.