Doudian is an e-commerce app launched by Douyin. If you need to complain about Doudian, you can follow the steps below:

1. Open the Doudian App and enter the "My" page.

2. In the "My" page, click the "Customer Service and Help" button.

3. Select "Online Customer Service" in the "Customer Service and Help" page to enter the online customer service page.

4. At the bottom of the online customer service page, you can find the "Feedback" button. Click it and enter your complaint content and submit it.

In addition to online customer service, you can also make complaints through Doudian's official account, Weibo, email and other methods.

The following are detailed complaint channels:

1. Doudian WeChat official account: Search Doudian, follow Doudian's WeChat official account, enter the official account, select online customer service, and enter your complaint content.

2. Doudian Weibo: Search Doudian, select Private Message or Comment on the Doudian Weibo page, and enter your complaint content.

3. Doudian Email: Send an email to support@doudian.com, indicating your complaint content and contact information.

Before filing a complaint, it is recommended that you first check the relevant regulations and policies of Doudian to ensure that your complaint complies with the relevant regulations. At the same time, it is necessary to keep relevant transaction records, evidence, and communication records with Doudian customer service for future reference and rights protection.