The solution to this problem is as follows:

1. Click the Pinduoduo icon. Go to the Pinduoduo homepage, then select the fourth option "Personal Center" among the four options at the bottom and click to enter.

2. After opening the "Personal Center", click "Click to log in" in the upper right corner, log in to your Pinduoduo account, and then you can enter your personal information.

3. Click the avatar to enter "My Profile". There is an option "Nickname" under the avatar. Click "Nickname" to modify the name, and then click Save.