Hello, only users who have registered for 90 days or more can set it.

If you have enough time, please set it up as follows:

1. Enter "My iTieba";

2. Select " Personal Settings";

3. Select "Signature File Settings" and upload a Baidu picture;

ps: Baidu will review the newly uploaded signature file. Review times can range from a few minutes to a few hours, so please be patient.

I hope my answer is helpful to you.