If your Baidu account has been registered for 3 months, please follow the following tips:
1. Enter the post bar.
2. Click on My I Post Bar in the upper right corner and click Settings on the right side of personal information.
3. There is a basic information. This is the ID map you posted.
4. Click the second button on the right to set the signature file.
5. You can add up to 5 signature files.
6. Signature file customization
I hope I can help you.